Louis Menand, in a great piece on voter irrationality from a few years back:
... after analyzing the results of surveys conducted over time, in which people tended to give different and randomly inconsistent answers to the same questions, Converse concluded that "very substantial portions of the public" hold opinions that are essentially meaningless-off-the-top-of-the-head responses to questions they have never thought about, derived from no underlying set of principles. These people might as well base their political choices on the weather. And, in fact, many of them do.
Findings about the influence of the weather on voter behavior are among the many surveys and studies that confirm Converse's sense of the inattention of the American electorate. In election years from 1952 to 2000, when people were asked whether they cared who won the Presidential election, between twenty-two and forty-four per cent answered "don't care" or "don't know." In 2000, eighteen per cent said that they decided which Presidential candidate to vote for only in the last two weeks of the campaign; five per cent, enough to swing most elections, decided the day they voted.
Seventy per cent of Americans cannot name their senators or their congressman. Forty-nine per cent believe that the President has the power to suspend the Constitution. Only about thirty per cent name an issue when they explain why they voted the way they did, and only a fifth hold consistent opinions on issues over time. Rephrasing poll questions reveals that many people don't understand the issues that they have just offered an opinion on. According to polls conducted in 1987 and 1989, for example, between twenty and twenty-five per cent of the public thinks that too little is being spent on welfare, and between sixty-three and sixty-five per cent feels that too little is being spent on assistance to the poor. And voters apparently do punish politicians for acts of God. In a paper written in 2004, the Princeton political scientists Christopher Achen and Larry Bartels estimate that "2.8 million people voted against Al Gore in 2000 because their states were too dry or too wet" as a consequence of that year's weather patterns. Achen and Bartels think that these voters cost Gore seven states, any one of which would have given him the election.
Or put another way:
(hat tip: Alex Tabarrok)
Ross Douthat is a former contributing editor at The Atlantic.