The exit polls are crucial to this research for two reasons. First, they provide data on the opinions and behavior of actual voters, not "likely" voters as identified from polls that ask their respondents to report—often unreliably—whether they will vote or have actually voted (depending on whether the poll is conducted before or after a particular election). Second, the exit polls constitute the only standardized and regular election polling done in every state of the United States, plus the District of Columbia, in presidential election years. This is particularly important for studying voting behavior in the context of competition for states' votes in the Electoral College.

Here are just a few examples of articles that have been published in the journal Political Science Quarterly, reporting on the exit poll data gathered in connection with national elections in 1988, 1992, 1996, 2000, and 2004. They help illustrate the range and depth of research made possible by exit polls:

• "The 1988 Elections: Continuation of the Post-New Deal System" was written by Everett Carll Ladd. The late Dr. Ladd was the world-renowned director of the Roper Center for Public Opinion Research who wrote widely on American politics. Among several major articles he wrote on elections that were published in Political Science Quarterly was this 1989 analysis of the 1988 election, which used exit poll data to compare the presidential choices of whites, blacks, and Hispanics in specific southern states. Ladd also used exit poll data to examine how other social groups voted, and how these groups differed in their party identification and their ideological self-identification. 

• In "The 1992 Vote for President Clinton: Another Brittle Mandate?" also by Dr. Ladd, the author used exit poll data from the 1992 election to focus on patterns of voting by ethnic and religious group and by gender, and to examine the possible effect of other factors, such as education level and general outlook toward government.

• A third article by Dr. Ladd, "1996 Vote: The 'No Majority' Realignment Continues," provided his analysis of issues illuminated by exit poll data gathered from voters on election day in 1996. Here Ladd used exit poll data to see how the publics in different states differed in their attitudes toward calls for "less government." He also used them to examine how religious service attendance was related to voters' presidential choices, their partisan identification, and their self-described liberal/conservative ideologies. Other extensive exit poll data on social groups and presidential and congressional voting were reported as well.

• "The 2000 Presidential Election: Why Gore Lost" is a 2001 article by widely respected Rutgers University political science professor Gerald M. Pomper, who provided an analysis of the 2000 presidential election. Dr. Pomper used exit poll data to compare presidential voting by different social groups in the 1992, 1996, and 2000 elections, as well as to examine how perceptions of national economic conditions and voters' financial situations influenced voting, and how other issues and evaluations of the candidates' personal traits affected voting behavior.

• Three widely respected political science professors from Michigan State University and Duke University were the authors of "The 2004 Presidential Election: The Emergence of a Permanent Majority?" Paul R. Abramson, John H. Aldrich, and David W. Rohde applied exit poll data to conclude that voter decisions were based largely upon retrospective evaluations in which President Bush was perceived by a narrow margin to have been a successful president as well as a leader who would be successful in combating terrorism. They also argued that pundits may have exaggerated the role of social divisions in the election.

Many more articles, as well as a number of excellent books, report and analyze exit poll results and apply them to a wide variety of political, social, historical, and media-related subjects.

In sum, exit polling and the regular archiving and dissemination of exit poll data are extraordinarily useful for academic scholarship, teaching, and all manner of research on American politics and society. In addition to developing and conducting exit polls, Warren Mitofsky took a particular interest in their archiving and use. For many years, the organizations involved in exit polling have provided these polling data without charge to the Interuniversity Consortium for Political and Social Research (ICPSR) and to the Roper Center for Public Opinion Research, on whose board of directors Warren was serving as chair at the time of his death. For many years from now, exit poll data will continue to provide important insights into our society and the body politic.

Why respond to exit polls? In a democracy, voting is, or at least it should be, the ultimate expression of public opinion. Thanks to the work of Warren Mitofsky and the other exit pollsters, we have a means of having our votes counted twice—once in the voting booth and once on the way out—and to have our opinions resonate well into the future. The more of us who participate in the exit polls, the stronger our voices will be. It is a great opportunity, and, for a good citizen, one not to be missed.

Robert Y. Shapiro is a professor of political science at Columbia University. Lisa Ferraro Parmelee is the editor of Public Opinion Pros. The passages above on the scholarly use of exit poll data were adapted from an affidavit prepared by Dr. Shapiro in September 2006 for the plaintiffs in the case of American Broadcasting Companies Inc., The Associated Press, Cable News Network LP, LLLP, CBS Broadcasting Inc., Fox News Network LLC, and NBC Universal Inc. v. Dean Heller, in his official capacity as the Secretary of State of Nevada, in the United States District Court for the District of Nevada.