As one who refused to vote for some 20 years, I wield a credential in the debate currently taking place in libertarian circles as to whether people should vote or not vote. (See a sampling of the vote vs. no-vote articles below.) I vote in favor of voting.
The reasons I didn’t vote for all those years were the ones usually cited by the don’t-vote crowd — that it’s morally wrong to vote for the lesser of two evils and that to vote in an immoral political system serves to sanction the system.
An extreme example would be Hitler running against Stalin. Which candidate would you vote for?