Leaning Voters

Candidate Support Measures

When researchers measure candidate support in preelection polls, there usually are respondents who initially support a candidate and those who say they are undecided (or refuse to tell the interviewer). Many researchers follow up with these “no opinion” respondents, probing to determine whether they lean toward supporting a candidate. Then these leaners are combined with the firmer supporters, that is, the choosers, to report total support. Experience has shown that this is the most accurate way of determining candidate support. Using this measurement method, researchers can separately analyze the truly undecided, a candidate's strong supporters, and those who are leaners.

Party Identification Measures

Because party affiliation is a psychographic attitude or orientation, rather than a hard-and-fast demographic characteristic such as gender, age, race, or educational attainment, different partisanship measures can have a real effect on the proportion of partisans in polls and other sample surveys. There are several standard measures that enable researchers to partition U.S. voters into a continuum ranging from “strong Democrat” through “independent” to “strong Republican.” One standard measure of party identification was developed by researchers at the University of Michigan for the National Election Studies:

It is these independents—the ones who choose Republicans or Democrats at this point—who are typically labeled “leaners.”

The Gallup Poll uses a similar measure, but frames the initial question, In politics today… Most researchers now agree that the Gallup measure allows for more short-term variability in party identification. Other polls use variations of these two methods. For example, the Minnesota Poll asks everyone who does not initially choose a party whether they lean toward the Democratic Party or toward the Republican Party; this is simpler and quicker and has the effect of providing a somewhat less cumbersome 5-point scale and does not partition partisans into weak and strong.

However, limiting party affiliation measures to closed-ended questions also may shunt those who consider themselves aligned with third parties into the leaner or independent categories. In some cases, especially in states where there are strong third parties (e.g. Minnesota), or in national elections when there is a strong independent party candidate (e.g. Ross Perot in 1992), these closed-ended questions may not allow researchers the analytical power they need to understand the electorate properly.

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