Comment: You waste your vote

First of all, in an election with millions of voters your vote does not make any difference whatsoever. In an election with a smaller electorate voting makes a difference. However, in big elections like this the winner is usually the one who is backed by the media.

Therefore the best course of action is to vote for your true preference. That way the probability that the next election features better (=closer to your preference) major party candidates is slightly raised.

Voting for evil is a wasted vote because:
1. it does not make a difference
2. it does not make your preference visible

There is no difference between Obama and Romney. Better the devil you know than the one you don't. And maybe Romney will even win, then a war with Iran will be more probable, almost certain (even with Obama war with Iran is not off the table).