BLINDED BY POLITICAL SCIENCE

On February 27, 1919, a radio and buzzer operator at Camp Hancock near Augusta, Georgia, took to a typewriter and composed a message to his superiors requesting a discharge. Sergeant First Class Harold Foote Gosnell was just six months into his military service. He had entered the army the previous fall, answering a draft notice just days after earning his bachelor’s degree from his hometown campus, the University of Rochester. As soon as he earned a license as a radio operator, commercial second grade, which required him to type twenty words a minute, he wrote military officials with the news. Eager to be shipped out, he bragged that he had also mastered the flag-signaling languages known as wigwag and semaphore. But by the time Gosnell was called to report for duty with the 47th Service Company at Hancock in mid-September, there wasn’t much war left on the calendar for him. Six months later, as the duties for a signal officer were receding, the obligations of a widow’s son came to the fore. In February, Gosnell’s mother wrote him from upstate New York to report that she had been sent to the Clifton Springs Sanitarium on account of her heart trouble. “Doctor says it’s valvular and muscular. Sometimes I can hardly get my breath and sometimes my heart pains me,” she wrote. “So that I think you ought to come home as soon as possible if you want to see me.”

Gosnell, twenty-two, was granted an honorable discharge, and left for his mother’s bedside. He had never planned on staying long in the military, anyway. From Hancock he had applied to graduate schools to study the new field of political science, but knew he couldn’t afford to attend any of them unless he received some financial support. Gosnell came from a working-class family and inherited its puritan temperament. One grandfather had been a Civil War veteran, and Harold’s father (who died when he was four) a vehement prohibitionist who joined the Republicans because they were “the party of the drys” and railed against the Rochester Chamber of Commerce dinner as “an annual drunk.”

Eight-year-old Harold had been captivated by the 1904 presidential election, which pitted two New Yorkers against one another. Gosnell was drawn to the swashbuckling profile of the Republican incumbent, Theodore Roosevelt, over Democrat Alton Parker, chief judge of the state’s appeals court, and learned to hum the party’s campaign ditty: Farewell, Judge Parker/Farewell to you/Teddy’s in the White House/And he’ll stay there too. In high school, he was a serious student and prolific artist, contributing hand-drawn covers with images of columns and coliseums for his high school’s Latin-language magazine, Vox Populi. When it became time to focus his attention, Gosnell knew he wanted to study how votes were won, and few places were as ripe for examination as Chicago.

In 1919, Chicago was already the country’s second-largest municipality—a lakefront skyline casting an ever-expanding shadow over a farrago of stockyards, bungalows, and rail lines unspooling across the Midwest—and had the lively political scene that a capital of monopolists and mobsters would deserve. “In spite of the city’s bad reputation for graft, bootlegging, gangster killings, election frauds, racketeering, and street violence,” Gosnell would later write, “buildings went up, superhighways were built, and the functions of an urban metropolis somehow were performed.”

That fall, Gosnell arrived in Hyde Park, where stone quadrangles had been planted to give the University of Chicago the dignified air of England’s legacy institutions. The university had opened its doors in 1892, one the first schools to do so with the declared goal of welcoming graduate students in search of Ph.D.s, still new to American academia and a matter of scant emphasis at prestigious old colleges like Harvard, Yale, and Columbia. Chicago had the architecture of an old place, which made the young school feel as far from the bustle of the Loop as Oxford did from London. Along the Midway, where the World’s Columbian Exposition of 1893 had unveiled Chicago as the model modern city, the school’s Harper Memorial Library had recently been erected as a medieval castle. Its crown studded with crenellated turrets, the building seemed to reflect a time-honored model of academic research. Those who studied society had typically done so from the comfort of a carrel, relying on historical documents to bolster their theories of how people live.

But at Chicago, tradition stopped at aesthetics. Through their work, young social scientists were constantly scheming to pull the university deeper into the scrum of the industrial metropolis just a cable-car ride away. “You have been told to choose problems wherever you can find musty stacks of routine records based on trivial schedules prepared by tired bureaucrats and filled out by reluctant applicants for aid or fussy do-gooders or indifferent clerks,” sociologist Robert E. Park warned his graduate students. Instead, he said, they should “sit in the lounges of the luxury hotels and on the doorsteps of the flophouses,” to observe their subjects in real time. “Gentlemen, go get the seat of your pants dirty in real research.” A shelf of the books produced by Park’s protégés throughout the 1920s and 1930s gave shape to the idea of a “Chicago school” of scholarship, but they could be mistaken, at quick glance, for a rack of dime-store novels: The Gang, The Hobo, The Gold Coast and the Slum, The Taxi-Dance Hall, Hotel Life, Vice in Chicago.

Gosnell, a small man who preferred his glasses round and his hair in a slick, parted wad, was dispirited to find little such adventurism in his department. Political science had few graduate students, and Gosnell had trouble finding friends among his peers. He had little affection for the department’s chair, Harry Pratt Judson, who also happened to be the university’s president and governed his department by terse memos on presidential stationery. With a background in constitutional law and diplomatic history, Judson had helped to establish one of the country’s first departments devoted to “political science,” an assertively modern name designed to set the new study of statecraft apart from the historically minded discipline once known as political economy.

But Gosnell felt his department was atrophying under Judson’s leadership. Like many of the early tribunes of the new discipline, Judson had little interest in actually bringing scientistic authority to bear on politics. “I do not like the term political science,” outgoing Princeton president and New Jersey governor-elect Woodrow Wilson had said at the 1910 conference of the recently established American Political Science Association. Human relationships, Wilson told the gathering at a St. Louis hotel, “are not in any proper sense the subject matter of science. They are the stuff of insight and sympathy and spiritual comprehension.” The previous year, Wilson’s predecessor as the association’s president had drawn a related, if less mystical, distinction. “We are limited by the impossibility of experiment,” said Harvard president Abbott Lawrence Lowell. “Politics is an observational, not an experimental science.”

In 1923, Judson finally relinquished his chairmanship, fanning Gosnell’s hopes that his department could at last modernize. The selection of Judson’s replacement may have looked like a default choice: Charles E. Merriam was the department’s only full-time professor. But he was also a giant in Chicago life. A native Iowan, Merriam had studied at Columbia, whose president Seth Low had stepped down from his office after winning the 1901 election to be the second mayor of the newly consolidated New York City. Merriam watched Low’s campaign closely and saw him as a model for the engaged public intellectual. Upon arriving in Chicago, Merriam quickly began lending his expertise to policymakers, blessing the initiatives of the modernizing metropolis with a scholar’s kiss. In 1905, he was asked by the City Club of Chicago to research municipal revenues. Three years later, after business leaders recruited architect Daniel Burnham to draw up a city plan, the mayor appointed Merriam to the Chicago Harbor Commission with a charge to implement a new waterfront agenda.

The idea that academic experts could tutor politicians reflected a popular Progressive era attitude, and Merriam became something of a utility man to reformers intent on fixing the broken city. He was elected to the city council in 1909 as a Republican and immediately agitated for the creation of a Commission to Investigate City Expenditures. The Merriam Commission uncovered graft and corruption involving party machines, winning its namesake few friends among his council colleagues but encouraging business leaders to view him as the kind of man they would like to see in charge. In 1911, Merriam ran for mayor, proudly publishing the names of his campaign contributors even though no law required him to. He won the Republican primary by antagonizing party bosses who never warmed to their nominee, but he narrowly lost the general election.

Still, the professor-turned-politician found himself energized by this new world. For Merriam, city government was also something of a refuge from academic politics, with slightly grander stakes. In 1919, he again sought the mayoralty, challenging William Hale “Big Bill” Thompson, a charmingly corrupt incumbent able to easily dismiss Merriam in the Republican primary. He returned to the university embittered by his decade at city hall, caught between two party machines and what he saw as the institutionalized perfidy of both, raising questions and fixing resentments that would inspire Merriam’s research agenda for the rest of his life.

To the extent that scholars believed they could explain why elections turned out the way they did, it was because they thought they understood how parties worked. Those who studied politics tended to study institutions, such as courts and legislatures, and the institutions of campaigns were political parties. Parties were an unmistakably important force in nineteenth-century politics, which Merriam knew intimately: by keeping the Union intact, the Republican Party had earned his father’s undying fealty, which he passed down to his son. During the 1896 election, Charles and his brother teased their father for being so reliant on Republican Party doctrine that they joked he had to go to the train depot in their small Iowa town and wait for the newspapers to arrive before he could be sure of what he believed. When Charles got to Chicago, he saw that in big cities, parties—with their clearly delineated hierarchies of county chairmen and precinct officers interlocked with neighborhood ethnic communities—were not merely organizations that told voters what to think but also delivery devices for the patronage spoils that won their loyalty.

But thanks in part to the efforts of reformers like Merriam, parties were weakening their hold on the political process. In 1907, Oregon became the first state to have its senators directly elected by citizens, instead of by state legislatures that often just rubber-stamped the picks of party bosses. In 1908, Chicago implemented primary elections for city offices, replacing party nominating conventions. Merriam was quick to realize that these primaries heralded an important shift in the culture of politics, as voters could no longer rely on party leaders to pick their standard-bearers. As a reformer, Merriam was encouraged by this, and as an academic he thought the shift of power to the citizenry made elections ripe for serious study. He sent a questionnaire to the burgeoning band of political scientists nationwide to get their opinions on what the actual effects of this more democratic system would be. “Does the direct primary bring out a larger vote than the convention system?” was one of Merriam’s nine queries.

The political scientists had little insight to offer Merriam. Because they had been so intent on unlocking the dynamics of institutions, they had largely ignored voters themselves. There was no governing theory of where people got their information and how they processed it, or the relative role that parties, issues, and candidate profiles played in their minds as they weighed their choices before election day. In fact, political science could do little to explain why people voted at all when the law did not require it. But to a first-year graduate student drawn to the rough-and-tumble of urban politics, nothing impressed like a professor looking for answers to these questions, and demonstrating equal fluency in scholarly footnotes and ward-by-ward returns. “Naturally, I took every course that Merriam had to offer,” Harold Gosnell later wrote.

The same forces that had foiled Merriam’s political ambitions were the ones that most fascinated Gosnell. He wrote his thesis on Thomas Platt, the New York senator whose machinations during sessions known as “Platt’s Sunday School Class” at the Fifth Avenue Hotel made him for a generation the dominant force in the state’s Republican politics. Gosnell said his goal was to mine “the social background, the personal qualities, and the technique of a typical state political boss.” That meant looking past the dynamics of institutions and into the motives of the individuals who drove them, and it meant reaching into psychology for tools foreign to political science. “What was there, first in Platt’s personality, in his general behavior, that led men to think that he could ‘do things’?” Gosnell wrote. The University of Chicago Press was interested in publishing Boss Platt and His New York Machine but unwilling to finance it, so Gosnell arranged a discount rate through his nephew’s brother’s publishing firm and paid to have it printed himself.

Gosnell received his Ph.D. in 1922, and Merriam approached him shortly after to offer a post as an instructor. Merriam was already deep into his efforts to rebuild the department from its decay under Judson; he had made clear he would not run again for political office and now hoped to use the university as his sole perch for improving local politics and government. He established a Social Science Research Council, with the goal of producing scholarship across disciplines—economics and sociology, in addition to political science—that would finally conjoin the university’s work with the life of the city. “I accepted the offer with alacrity,” Gosnell later recalled.

Gosnell affectionately called Merriam “the Chief” and the two men shared an intimate love of urban politics, but a methodological gap was opening up between them. Gosnell had taken graduate courses in statistics and mathematics and was eager to apply numbers to the political questions that interested him. “While Charles E. Merriam gave lip service to quantitative, psychological, and empirical research he was essentially a philosopher dealing with ideas and an activist dealing with programs,” Gosnell wrote. “While he liked to see others strive to be scientific, he personally was a philosopher high in the clouds spinning out ideas, not bothered by the mundane search for facts.”

In the spring of 1923, Merriam approached Gosnell with an idea for a joint research project that would merge the older man’s activist agenda with the younger’s interest in modern research methods. Chicago voters had just booted Big Bill Thompson for a Democratic judge named William E. Dever in a mayoral election that seemed to dominate citywide attention. Indeed, the conversation in political circles focused on the fact that turnout was surprisingly high. But Merriam, fueled by intellectual curiosity and residual bitterness over his own loss to Thompson, turned his attention to those who never cast a ballot. During his own campaigns, Merriam had worked on expanding the electorate by recruiting new voters, especially among new immigrant arrivals who had yet to fall under the machine’s spell. Now the city had about 1.4 million adults, but only 900,000 were on the electoral rolls; among them, 723,000 cast a vote for either Thompson or Dever. It galled Merriam, as it had during his own campaigns, that barely half of the city’s eligible voters had been involved in picking their leader; the apathy of the rest helped keep the machines in power. He suggested to Gosnell that they investigate the reasons the nearly 700,000 nonvoters had for opting out—and what might be done to lure them into the process.

Gosnell prepared a survey to ask them, relying on U.S. Census data to guide him in each of the city’s fifty wards toward a representative mix of respondents. Gosnell and Merriam decided to use a hybrid survey, which would have multiple-choice questions but leave room for free answers, an approach they believed should yield a healthy batch of data but also qualitative responses with richer texture. All interviews would be done face-to-face at people’s homes, so Gosnell had to train graduate students to navigate the city’s racially and ethnically complex neighborhoods, where he worried they might not find a warm welcome for outside researchers asking nosy questions. Gosnell dispatched a Swedish-speaking student to a heavily Swedish neighborhood, and hired a Polish interpreter elsewhere. (Of the sixteen doors the professor knocked on himself as part of the project, one happened to belong to writer Ben Hecht.) The researchers’ forms were then coded, and the data moved onto punch cards so they could be tallied by machine. The university did not have the proper equipment, so Gosnell went to city hall and found a clerk in the comptroller’s office willing to run the cards on his own time for one dollar an hour. When Gosnell looked over the six thousand answers his students had gathered, he was pleased by one particular sign of their diligence. Those assigned to the city’s so-called Black Belt, where Gosnell had feared that the response rate would founder, had been so aggressive that African-Americans now overwhelmed the sample. Gosnell removed some of them to maintain the delicate demographic equilibrium essential to the project’s credibility.

Gosnell’s findings, with edits by Merriam, were assembled under both men’s names in Non-Voting: Causes and Methods of Control. Published by the University of Chicago Press in August 1924, the book—released just months before a presidential election—received national attention for trying to explain the fact that women’s suffrage had not dramatically increased voter participation. (Gosnell found twice as many women as men who didn’t vote.) But Gosnell’s conclusions, that “general indifference” led people to stay home, made less of an impact than his technique. It was the first major political science study to rely on random sampling in a way that broke down the sample by different demographic attributes.

“If scientific methods seem hitherto to have found too little favor with American politicians, political scientists must admit that they themselves are largely to blame,” Harvard professor A. N. Holcombe wrote in a short but enthusiastic article in the American Political Science Review. “But on the basis of this first experiment at Chicago it ought to be possible,” Holcombe suggested, to draw conclusions about elections “with all the assurance of a chemist proving the quality of a new paint-remover or a biologist testing a germicide.”

Gosnell was already thinking in those terms. He had begun meeting with social psychologists who recommended tools that would allow him to find out what, if anything, could change nonvoters’ behavior. The psychologists explained the rudiments of a field experiment: Gosnell could introduce what they called “controlled stimuli,” in this case reminders of a coming election, and then measure their effect. By setting up a control group, whose members did not receive the treatment, and comparing their vote performance against the rest, Gosnell would be able to measure whether various appeals could turn people into voters.

This was the scientific method at work, and despite their title no political scientist appeared to have ever tried such an approach. Gosnell had observed nonvoters and had theories about their behavior based on why they said they did not participate. Now he became convinced that only a randomized-control experiment would allow him to see if anything could change that. This ambitious agenda was making Gosnell’s research a lot more expensive than the typical office work practiced by traditional politics scholars. The 1923 poll had cost five thousand dollars. Even in Judson’s absence, getting the administration of Robert Maynard Hutchins, one of his successors, to back research forays into the messy world of urban politics was not easy at a school Hutchins was elevating into a global citadel of canonical study. “We were hopeful that democracy could be made to work,” Gosnell wrote. “But President Hutchins thought otherwise. All worthwhile ideas were to be found in the Great Books. Social science research in a metropolis was trivial.”

But the Chief had his own sources of money and so started shaking the trees for his protégé, approaching his former campaign donors and business leaders. The most lucrative avenue was the Rockefeller family, whom Merriam reached through Dr. Beardsley Ruml, a psychologist, PR man, and Macy’s department store official who as a Roosevelt administration official later helped design the country’s first withholding system for federal income taxes. Gosnell was dazzled by Ruml, privately sketching caricatures showing the “financial genius as bargain basement statue of Buddha,” able to bring Rockefeller cash into Merriam’s account to support further research.

Gosnell conceived his experiment as a two-stage study: the first would measure whether citizens who were not registered could be pressured to sign up, and the second would test what could be done to get already registered voters to turn out at a higher rate. Gosnell identified six thousand adult citizens scattered across twelve Chicago zones, and arbitrarily divided them into two groups, checking to ensure that they looked demographically similar. One group would be his treatment sample and the other his control. “The study was aimed to give an answer to the question whether the non-voter is such by a deliberate act of will or whether he is a non-voter from ignorance but not a deficiency of public spirit or alienation,” Gosnell later wrote.

In the fall of 1924, Gosnell sent postcards emphasizing the importance of registering to vote before the presidential election that November. (In addition to English, Gosnell drafted versions in Polish, Czech, and Italian.) The postcards had their intended effect: people who received them were nine percentage points more likely to register. Then Gosnell prepared another set of two postcards for the 1,700 voters who were unmoved by the first appeal, one with another nonpartisan message about the urgency of registration and the other with a cartoon picturing nonvoters as “slackers who fail their country when needed,” according to the caption. Both pushed people to register at a higher rate than the original control group. In the end, 75 percent of those who received at least one of Gosnell’s cards ended up registering, while only 65 percent of nonrecipients did. He had put about three hundred new voters on the city’s rolls who wouldn’t have been there otherwise.

The next February, Chicago would elect aldermen, as the fifty members of its city council were known, and Gosnell set his sights on the nearly 2,200 new voters who had registered after receiving one of his notices. (Most, he knew, would have registered without his intervention.) Gosnell drew up another cartoon, this time depicting “the honest but apathetic citizen as the friend of the corrupt politician.” Again Gosnell left his mark on the election: 57 percent of those who got the cartoon turned out to vote for alderman, compared with 48 percent of those who didn’t.

Gosnell did his calculations by hand, and as he looked more closely at these numbers, he realized that his mailings were most persuasive among new residents, who Gosnell concluded had few other sources of information on how to vote, and in districts where party organization was weakest. In demographic terms, they had the most impact on “the native-born colored women and the women born in Italy,” wrote Gosnell. The reason, he found, was that the League of Women Voters was directing most of its attention toward native-born white women and little toward minorities. Gosnell’s conclusions were obvious—mobilization efforts can have the biggest impact in places where little else is pushing voters to the polls—but no one had ever before quantified them.

It was likely the first field experiment ever conducted in the social sciences outside psychology, and it was well received when published in book form, as Getting Out the Vote, in 1927. Political scientist George Catlin wrote that Gosnell’s study “has the high merit of being precisely a scientific social experiment.” This time Gosnell’s innovation jumped from scholarly journals into the news pages. “This study is not only a model of careful method in a virgin area of political exploration,” Phillips Bradley wrote in a New York Herald Tribune review, “but offers some pretty plain evidence that what has here been done privately in the case of a few thousand voters should become a regular part of our official election procedure.”

But Gosnell never ran another experiment. In the 1930s, he turned his attention to pioneering studies in black politics and machine organizations, goaded on by Merriam’s continued bitterness about the forces he believed had unfairly denied him his place at city hall. “Perhaps Mencken is right,” Gosnell consoled his mentor. “The people usually vote for crooks.” Despite the enthusiasm that greeted Gosnell’s method for studying campaigns, no one tried to copy him, replicate his study, or build upon it. After printing Gosnell’s article, the American Political Science Review did not publish another finding from a randomized field experiment for a half century. During that time, political science grew into a major discipline obsessed with studying voters and elections, but to do so it returned to the library and stayed off the street.

THE FEW EFFORTS by political scientists to revive Gosnell’s experimental technique proved evanescent. In 1954, University of Michigan professor Samuel Eldersveld used new statistical methods to dispatch mail, phone calls, and in-person canvassing visits across eight hundred Ann Arbor residents according to a random-assignment procedure, and then measured their relative effectiveness on turnout. Eldersveld’s experiment had more impact on local politics—three years later, he succeeded where Merriam had failed and was elected mayor of the college town—than on the academy. Afterward, entire decades would pass without a single randomized field study about political behavior being published in a scholarly journal.

Political scientists didn’t take to experiments in part because they knew that they would never control the laboratory. The party machines that dominated most American political activity lacked the self-examining impulse, and were unlikely to welcome ivory-tower visitors into their clubhouses. Meanwhile, campaign finance laws and the universities’ nonprofit tax status made it hard for them to do anything on their own that, even inadvertently, advanced the interests of a specific party or candidate.

Political scientists instead happily flapped about in deep pools of new data generated by a postwar revolution in research methods. The ubiquity of household telephones made large-scale survey-taking possible, and increased computing power permitted complex statistical regressions. Specialists in the new field of polling developed protocols for assembling interview samples that would reflect the broader population, and for scripting survey questions to make sure they elicited meaningful responses. Everyone started doing polls, but quality was inconsistent. In 1948, most pollsters flubbed their electoral predictions—leading to the Chicago Tribune’s morning-after “Dewey Defeats Truman” front page—because they stopped talking to voters in the race’s closing weeks, therefore failing to pick up on a late movement toward the incumbent.

One of the pollsters who did not make that error was Angus Campbell, a social psychologist who had spent the war years in a research office of the Department of Agriculture, modeling how consumers would react to the conflict’s end so that policymakers could anticipate what they were likely to do with their war bonds. In 1946, Campbell and several colleagues decamped to Ann Arbor, where the University of Michigan built a new Survey Research Center around them. After the 1948 election, Campbell ran a post-election survey to make better sense of Truman’s comeback. As 1952 approached, Campbell mapped an ambitious plan to track the attitudes and opinions of the electorate, unfurling a series of lengthy questionnaires that would be used to interview voters nationwide throughout the election season.

Standards were changing rapidly, and it was no longer acceptable for a professor to publish a credible paper on public opinion that used data gathered by his own students, as Gosnell had in 1923. In the late 1950s, Gosnell, then working as a State Department analyst, approached pollster Clyde Hart to propose a reprise of his Chicago voting studies and suggested he might be able to raise ten thousand dollars to fund it. “He looked at me as if to say, ‘Where have you been, Rip Van Winkle?’ ” Gosnell recounted to a gathering of pollsters to which he had been invited by an old friend, Elmo Roper, who had been a pioneer of national surveys during Franklin Delano Roosevelt’s bid for a second term.

“Don’t you remember Elmo’s famous comment after the 1948 election?” Gosnell went on. “This was a priceless comment about the price of polling. What were the lessons learned from that slight discrepancy between the polls and the election results in that Dewey-Truman contest? Was it that last minute change in calculating the turnout? No, none of these things. Elmo put it in a nutshell. The 1948 polls showed that polling is a complicated business. It is going to cost customers more.”

The costs did not dissuade Campbell, who was looking to develop the first systematic effort to explain how presidential elections were decided. His 1952 survey came with a $100,000 price tag, covering interviews with 1,900 subjects and asking 224 different questions. The project, which later became the American National Election Studies, grew into the definitive data resource in political science: a massive biannual polling project that was expensive to collect but created a permanent repository of data on who voted and what they said about why, all with a consistency that made it easy to track changes through a campaign and from one year to the next. Campbell’s questionnaire took an expansive view of its subject, with questions about not only the election under way but practical matters of political behavior (“did your coworkers’ opinions influence you?”) and philosophical approaches to citizenship (“should one vote if his party can’t win?”).

The responses guided Campbell toward nothing less than an all-encompassing theory of how elections are decided. Along with colleagues Philip Converse, Warren Miller, and Donald Stokes, Campbell concluded that a person’s partisan identification was the strongest predictor of how they would vote in national elections, even better than asking them where they stood on any particular issue. Parties were glorified social clubs, pulling people in because of class, regional, or religious ties and keeping them for the long term—with a sort of thoughtless choice resembling the inertia that led people to take the same jobs as their relatives. Individuals rarely switched parties over the course of a lifetime. Campbell and his colleagues described individual voting decisions with the image of a funnel: citizens’ social and psychological loyalties narrow them into a party, which usually guides them toward a candidate.

For all that, though, there were short-term disruptions that pushed voters toward a candidate of the other party. After all, the same voters who had decisively elected Franklin D. Roosevelt four times swung broadly behind a Republican, Dwight Eisenhower, less than a decade later. Voters were attached to parties, but those bonds were generally breakable, the Michigan scholars argued, and sometimes a candidate comes along who is so appealing that his personal attributes overwhelm partisan loyalties. Converse liked to compare it to a big wind sweeping through a field of wheat, which leaves every stalk leaning in the same direction, although bending some more sharply than others.

In 1960, Campbell and his colleagues introduced this metaphor in the book The American Voter, the first universal, data-intensive study of electoral behavior, but the argument would prove poorly suited for its era. American politics convulsed in the late 1960s and 1970s, following the passage of the Civil Rights Act, and a partisan-driven model seemed tragically anachronistic. Within two decades, the South had become the base of Republican presidential coalitions even as most of its residents remained Democrats, and political scientists began to thrash about for a new way to explain the American voter. It became popular to say that people deserved more credit for the political choices they made. “The perverse and unorthodox argument of this little book is that voters are not fools,” V. O. Key Jr. wrote to start his 1966 treatise, The Responsible Electorate, which argued that many voters were “switchers,” rationally alternating between parties each election to find the candidate closest to them on the issues.

After Richard Nixon’s reelection in 1972, Michigan’s Warren Miller desperately rewrote the American Voter theory to keep up with changing times. The survey data for that year had shown, for the first time in the two decades of the national election studies, that party influence over how voters chose among presidential candidates had diminished markedly. The “issueless” fifties, as they put it, had been followed by a decade in which the country was politically riven on fractious matters of war and peace, identity and liberty, that crossed the old party lines. Voters ditched their social clubs for the candidate who stood closest to them on policy. The Michiganders explained this by pointing to a way the electorate had fundamentally changed: Americans were better educated than before, and went to their polling places with a more enlightened interest in affairs of state. “Voters with a college education are better informed politically,” they wrote, and “therefore, more likely to make a vote decision on the basis of policy preferences than are less well-educated individuals.”

Such academic theories were barely acknowledged by those who worked in politics, and when they were it was often with skepticism. In fact, those on both sides of the Nixon reelection battle scoffed at the American Voter team’s reading of the landslide. The president’s pollsters, Bob Teeter and Fred Steeper, disputed the idea that “the 1972 patterns portend great ideological battles for future presidential elections,” as they wrote, “and that the political parties must change their issueless ways in order to cope with an increasingly polarized electorate.” Relying on their polls for Nixon, Teeter and Steeper delivered a new theory for what had prompted so many Democrats to unmoor from their party and dock with Nixon. They suggested that swing voters were no longer voting on issues, such as Vietnam or the economy. They may not have even had strong ideas of the right and wrong positions on the issues. Now they were giving their votes to the candidate who seemed best able to “handle” those challenges. Nixon, like Eisenhower, had established himself as a more credible leader on the issues of the day. This “candidate-induced issue voting,” as Teeter and Steeper called it, had as much to do with the candidates as the issues.

They found an unlikely ally in Samuel Popkin, a University of California, San Diego, political scientist who served as a campaign adviser to the man Nixon had defeated, George McGovern. In 1972, Popkin had been a Harvard statistics professor when three of his undergraduate students, including Pat Caddell, sold the South Dakota senator his first poll for five hundred dollars. Soon Caddell was the chief strategist for the Democratic nominee’s campaign and enlisted Popkin, who was only thirty then but still nearly a decade older than his excitable protégé, to join the recently minted Cambridge Survey Research trio as an in-house wise man and extra hand with the numbers.

After the campaign, Popkin aggregated all the polling data and tried to answer the same question the Michigan scholars had tackled: why had McGovern lost to Nixon by more than twenty points? McGovern’s early polls suggested the race should be competitive. But as it went on, Nixon’s lead widened, and the issues alone couldn’t explain such a gap. Even those who agreed with the dovish, liberal McGovern on his top foreign and domestic priorities were drifting away. In September, McGovern led Nixon among voters who considered Vietnam the most crucial issue, believed that the United States should withdraw immediately, and supported a guaranteed family income, by a margin of 52 to 38. By the end of the campaign, McGovern had lost them all. His internal polls showed him trailing even among those who thought the military budget should be drastically reduced. McGovern hadn’t lost voters because he was out of sync with them on issues, Popkin argued, but because they thought he wouldn’t be able to do anything about those policies. They watched McGovern during the campaign and concluded he was incompetent.

Popkin thought voters were much savvier than the Michigan studies had initially cast them, but that even those with college diplomas could never gather all the information necessary to weigh the entire set of costs and benefits attached to each issue or candidate. They weren’t making a buying decision, because they wouldn’t get the product they eventually chose. Instead, thought Popkin, it made more sense to think of them as investors, who knew whatever information they gathered to inform their decision making would require time and effort. So when it came time to choose a candidate, they relied on shortcuts. They interpreted symbols and looked for cues where they could find them, and then extrapolated. In one of Popkin’s favorite examples, when voters saw Gerald Ford fail to shuck a tamale before biting into it, they interpreted it as a sign that he did not understand issues facing Latinos. (Popkin had worked as a campaign adviser to Jimmy Carter in 1976.) Popkin called this “gut reasoning.”

Election scholars had ignored large swaths of modern psychology, which was increasingly identifying ways in which people were neither socially preprogrammed toward certain attitudes nor walking calculators able to make perfectly rational choices. In other academic disciplines those theories of human behavior had long fallen from vogue, replaced by a less elegant one. In the 1970s, two Israeli psychologists, Amos Tversky and Daniel Kahneman, began to document the ways that people were incapable of deciding rationally, and in fact kept making the same mistakes over and over again. Around 1980, a young economist named Richard Thaler began translating these insights to the way people handled money, and it became readily apparent that people weren’t as rational as economists imagined them to be. When forced to make decisions, people lacked a steady set of preferences. What they had instead were unconscious biases that made them bad at assessing situations and accurately judging costs and benefits.

But even a decade later, this basic insight—people are flawed, if well-intentioned, beings—had barely penetrated the political science department. “The science half of political science is to some extent a bit of a misnomer,” says Thaler, who in 1995 began teaching at the University of Chicago, just blocks from where Gosnell and Merriam had designed their field experiment to study voter behavior seven decades earlier. “At least no one has been quite ready to agree on what the science part of it is.”

In his 1991 book The Reasoning Voter, Popkin introduced a theory of voter activity equally informed by behavioral psychology and his own experiences within presidential campaigns. “These contests are commonly criticized as tawdry and pointless affairs, full of dirty politics, dirty tricks, and mudslinging, which ought to be cleaned up, if not eliminated from the system. In their use of sanitary metaphors, however, many of these critiques confuse judgments of American culture with aesthetic criticisms of American politicians,” Popkin wrote. “They do not look closely at how voters respond to what they learn from campaigns, and they do not look closely at the people they wish to sanitize. If campaigns are vulgar, it is because Americans are vulgar.”

This was a theory of the electorate that could make political professionals, increasingly under attack as overpaid Svengalis of spin, feel good about what they did for a living. In December 1991, Popkin wrote an oped for the Washington Post whose headline blared “We Need Loud, Mean Campaigns.” Paul Begala, a Democratic consultant, clipped Popkin’s article from the paper and handed it to his partner, James Carville. Carville and Begala, who had recently joined Bill Clinton’s campaign as lead strategists, were both loud, occasionally mean, and always unrepentant about the clangorous tone of the campaigns they ran. Popkin’s essay offered affirmation. Carville called Popkin to request a copy of The Reasoning Voter. Not long after, Popkin joined the campaign as an adviser. “He’s one of us,” says Begala. “He gets it.”

Popkin spent much of 1992 collecting polls and past election results to build simulations of electoral-college scenarios that could get Clinton to the necessary 270 votes. The results informed key strategic decisions: which states would get offices and staff, visits from the candidate and his family, and a precious share of the campaign’s budget for paid campaign communication with voters. “It’s an important decision in any war,” says Popkin. “Who’s going to pick the theater of operation?”

But as those strategic choices atomized into a series of tactical options, Popkin was amazed at how little he actually felt he knew. For two centuries Americans had been electing presidents, and for half of one century specialized scholars had been trying to rigorously study that process. Yet they had accumulated little information useful in deciding how to spend campaign dollars. As one of the few political scientists with access to a presidential campaign’s war room, Popkin had his feet in the worlds of people who practice politics and the people who study it, and neither field impressed him with its ability to judge what actually won votes. Popkin thought campaigns had learned to be smart about how they picked their theaters of conflict, but once assigned to one, a general had only his instinct to rely upon in deciding whether to battle in the air (buying TV and radio ads) or on the ground (the hand-to-hand mobilization known as field).

“It’s the all-time question of every defense department in the world: army versus air force. What is the ultimate value in any war of a soldier versus a bomber?” asks Popkin. “You can target a state, and everyone could say ‘the swing voters are in Peoria’ and ‘Oprah costs this many dollars.’ ” But that information alone was of little use. “No one has any idea of the value of the ad versus a phone call from a friend,” he goes on. “If you have a dollar to spend, do you spend it on an ad or do you spend it on a phone call? And if you only have money to spend on ads, do you give one person fifty ads or two people twenty-five? Nobody knows.”