Soooo...what do we do?
Join the constitution party. If no one votes third party because they're afraid of wasted votes, we'll never get rid of the duopoly. I say this as a libertarian, not as a social conservative.
I have been thinking in a similar fashion for a long time. However, I am reconsidering my position. Perhaps my mistake has been to watch from outside the party system, then vote for the most conservative candidate.
I am strongly considering, for the first time, joining the Republican party so that I can participate in the primaries and influence the conservatism of the party.
Maybe you have already done this. If not, perhaps this is what needs to happen in order to be sure Republican candidates are conservatives.