You're saying you only want to vote for a party that could win. Why? For the satisfaction of feeling like you made a difference? If the polls showed that the "greater evil" party was winning by a large margin, would you vote for that too because the lesser evil one has zero chance?

People who vote against their own interest and focus on over-emotional bipartisan feelings are exactly the reason America's government keeps doing things that people don't like. They're so afraid of the "greater evil" that they'll even kill the greater good in a futile attempt to avoid it. The republicans will still keep on winning every couple of cycles, just as they always have. Voting for one of the two major parties is really a vote for the status quo of alternating republican and democrat governments. It's like sports, no team is ever really going to win. They just keep switching places.