In today’s OC, Cato fellow Will Wilkinson has one of the better short summaries you’ll find on why low voter turnout isn’t necessarily a bad thing. Basically, a) high voter turnout is often a sign of high civic antagonism and partisanship, b) many people are ignorant of the issues and shouldn’t cast a ballot, which isn’t a bad thing because c)) there is no indication that people vote their narrow self-interest or class interest. He might have added d) that the fewer people who vote the more each vote actually is worth, so from a self-interested point of view, it is better for me if you don’t vote.
The main objection I would offer is that Wilkinson’s argument — based on the idea that the function of voting is to select amongst various policy alternatives — is itself only part of the story. Voting serves many purposes, and I actually think its least important role is in choosing policy. Far more important is the Schumpeterian function — voting is a way of cycling elites through government. That in itself does not require higher voter turnout, except that the cycling of elite requires the consent of the governed. High voter turnout can signify a large degree of public consent for the system of government.
The broader point is: Wilkinson’s arguments notwithstanding, ignorance of the issues is not necessarily a reason not to vote.
More: Read Don Butler on why we do, and should, vote.