Is it time to start voting for third parties?

Well uming that you want DADT repealed, and you want to see gay marriage, would voting for a single republican help? And voting for a third party candidate would only hurt. If we merely had 3 less GOP congressmen we would have DADT repealed already, and we'd have gay marriage already. So all you have to do is vote against the GOP and give congress 60 liberal senators (which they do not have).