Q. What is the value of polls that match an incumbent or specific candidate against a “generic” Republican or Democrat? Some of these polls give respondents an extra option by choosing the answer “it depends on the candidate,” and some just leave as the only other choice being “undecided” or expressing “no opinion.” I assume that makes a difference.

The so-called “generic ballot” provides a snapshot of how an incumbent president would fare against an unnamed challenger from the opposing party. In this regard, the question is simultaneously posing a referendum on the incumbent and a test of the popularity of the other party. The trend on this question can be informative. In Pew Research Center polls in July and August, Barack Obama ran about even with an unnamed Republican; he held a significant lead earlier in the year. At the same time, however, the generic ballot has no predictive power, particularly at this very early stage in the presidential race.

Generic questions that invite respondents to say “it depends” will certainly get a much higher percentage declining to choose between the candidates. That may be a more honest reading of public opinion at this point in the campaign, but is even further from simulating the actual choice that voters will face in November 2012.

The so-called “generic ballot” tends to be a good predictor of the outcome of congressional elections in the off-years. Many survey organizations, including Pew Research Center, use such questions to help gauge the size of possible swings in party representation in Congress. But because presidential elections ultimately hinge on a much more personal choice, with far more information available to the average voter, generic questions are rarely used once the field of nominees has been winnowed.

Scott Keeter, Director of Survey Research, Pew Research Center
President, American Association for Public Opinion Research, 2011-2012