Louis Menand has a review article in The New Yorker entitled “Fractured Franchise: Are the Wrong People Voting?,” a freebie for net users. Menand discusses “The Myth of the Rational Voter: Why Democracies Chose Bad Politics” by George Mason University Economist Bryan Caplan.
Menand’s review is really a spingboard for mulling over some theories of why people vote the way they do. Along the way, he provides this disturbing rant on political illiteracy:

The political knowledge of the average voter has been tested repeatedly, and the scores are impressively low. In polls taken since 1945, a majority of Americans have been unable to name a single branch of government, define the terms “liberal” and “conservative,” and explain what the Bill of Rights is. More than two-thirds have reported that they do not know the substance of Roe v. Wade and what the Food and Drug Administration does. Nearly half do not know that states have two senators and three-quarters do not know the length of a Senate term. More than fifty per cent of Americans cannot name their congressman; forty per cent cannot name either of their senators. Voters’ notions of government spending are wildly distorted: the public believes that foreign aid consumes twenty-four per cent of the federal budget, for example, though it actually consumes about one per cent.

It goes on. Not a pretty picture, nor a compelling argument for increasing voter turnout in general. Similar scary litanies about “low-information voters” have dogged U.S. democracy for a while now. The preferred assumption is that the political illiterati are voting mostly for the other party, or alternatively that most of them are not voting at all.
Menand sees an elitist strain in Caplan’s thesis:

The average voter is not held in much esteem by economists and political scientists, and Caplan rehearses some of the reasons for this. The argument of his book, though, is that economists and political scientists have misunderstood the problem. They think that most voters are ignorant about political issues; Caplan thinks that most voters are wrong about the issues, which is a different matter, and that their wrong ideas lead to policies that make society as a whole worse off….Caplan thinks that the best cure is less democracy. He doesn’t quite say that the world ought to be run by economists, but he comes pretty close.

According to Menand, Caplan also advocates dubious reforms, such as an “economic literacy” test for voters, and giving extra votes to people with “greater economic literacy.”
Menand also touches on the phenomenon of “shortcut” voters — those who don’t follow issues closely, but rely on the judgement of friends, relatives or political parties in deciding who to vote for. The latter may be more common in western Europe’s democracies, where turnount is much higher and where political parties and party-line voting traditions are stronger. Building Party cohesiveness is easier in Parliamentary systems, but that doesn’t mean Democrats can’t do more to encourage straight ticket voting in the 17 states where it is permitted. Such ‘shortcut voters’ may well provide the margin of victory in any number of close races.