Selwyn Duke says it short and sweet in “Why Most Voters Shouldn’t Vote”:

Most of us agree that having an educated populace is a prerequisite for a sound democratic republic. We also know that not everyone is well-educated. Thus, it cannot be a good thing for everyone to vote. For those of you who had trouble following that line of reasoning, please remember that Election Day is November 5.

And one needn’t be disenchanted with universal suffrage to agree. It’s one thing to have one man, one vote; it’s quite another to have one man, one obligation to vote. Yet we still hear that it’s our “civic duty” to go to the polls. Well, no, actually, it’s a civic duty to make ourselves worthy to do so.

This “vote first, ask questions later” idea reaches the very nadir of inanity when it manifests itself in get-out-the-vote drives, which can quite correctly be defined as an effort to rally the idiot vote disguised as a noble exercise in democracy.

P.S. Remember when Mankiw got in a little trouble for this?