Let's say you convinced someone else to vote the same way as you (2 votes), who'd you vote for?
A democrat who wants to legalize pedophilia, wants to kill all intellectuals and want to rape your wife or your husband. has 50 votes
A republican who likes war, wants to audit fed, wants to redistribute wealth, wants to legalize weed, wants to leave it up to the states. has 49 votes
A third party who hates war, wants to audit fed, wants free market, wants to legalize weed, and is against bail outs, wants to leave it up to states. has 5 votes.
I think we can all agree that voting based on "lesser of two evils" is bad in most cases because both candidates are usually the same establishment, big government, and is the same. But when you truly have one candidate that is the lesser of two evils... I think it might be time to do your duty to make sure that the greatest evil wont win.
Your duty is to make sure you elect someone who will have the best chance at protecting you and as much of the Constitution as possible, doesn't matter D, R, L, G, C or etc. In life you gotta make calculated decisions on which would get the best results.