Swing!

In the United States's two-party system, swing voters wield an inordinate share of power. With partisans almost evenly divided, the "undecideds" are often the real arbiters of American elections, and the ads and speeches candidates create are tailored to these mighty in-betweeners. Recent polls estimate that 40 percent of the American electorate identifies as independent, making them a larger group than either Democrats or Republicans. They sometimes seem to inhabit hallowed ground a notch above all the knee-jerk partisans, but new evidence suggests such status is largely undeserved.

So who exactly are the independent voters—and how do they make up their minds?

Impartial—Or Just Plain Apathetic?

Pure independents—those who don't slightly lean toward either party—show the least interest in politics among all surveyed blocs. Fifty-seven percent of the time, they can't even supply a correct answer to the question of which party controls the House. Worse (or thankfully?), they are also the least likely to actually cast a vote.

Independent—Or Members of the Mob?

An average of 20 percent of voters don't pick a candidate until the last two weeks of a campaign. One study from the University of Minnesota found that some late deciders may look to social consensus as a way to make decisions. "They [may] just want to appear thoughtful or to hedge their bets and pick the winning candidate," the authors suggest.

Deliberate—Or Illogical?

Which candidate would you rather have a beer with? The answer to the classic but irrelevant question matters much more to voters who are on the fence, Italian researchers report in Political Psychology. People unsure who they will vote for are more likely to consider a candidate's personality, especially that of the better-known incumbent.

Open-Minded—Or Conflicted?

Americans who feel pulled in two directions about core political issues are likely driven by contradictory values, research shows. Those who say they support both individualism and egalitarianism, for example, respond with high levels of ambivalence to questions about government, political parties, and social welfare policies, so they struggle to take a stand.