As a Christian, I cannot in good conscience vote for a pro-abortion, pro-gayzista candidate.
As a gun-owner, I cannot in good conscience vote for an anti-gun candidate.
If you can do that, more power to ya.
You nailed it.
That would make sense in a world of perfect choices and clear delineations. Sadly, this world is one of degrees.
The formula you've espoused is:
1. Won't vote for less than perfect GOP candidate.
2. That candidate loses.
3. A candidate that votes 0% to your standards wins.
You've set up a scenario in which your worst choice wins. That's not logical or sensible. If a guy like Scott Brown or Sen. Mark Kirk (R - IL) wins you have a chance to work with them and worst case you get their votes so that you control committees and the legislative agenda. You're better off with sheep like that, being lead by lions like Cruz, Paul and Lee, than a Congress full of Democrats for whom Natural Rights are an abomination to be destroyed.
In the end Politicians sell a product: their vote. They must be reelected and therefore have to play ball somehow. It's easier to get a RINO to come to your side, than a Democrat. That's the facts of this world.