I firmly believe casting a vote for the party that you dislike the least is not only futile but is very dangerous.

If Dennis Kucinich were heading up a third party, I might vote for him. Or might not, I'd have to decide if I wanted to waste my vote against the theocrats. He's not forming a party, nor is anyone else. Our only chances for a third party this year are a Christian theocrat party or a Tea Party idiot party. So, in the absence of a liberal, socialist, green, truthful, or financially responsible third party, who should I vote for this year?

In what way is it futile and dangerous to vote against the greater evil? In what way is it NOT futile dangerous to fail to vote against the greater evil?