It isn't DeMint that brought the numbers in Congress down. It is a combination of factors. I'm not privvy to any scientific data here, but from my perspective, the reason the GOP is way down in Congress relates to the Bush Administration's failure to adequately counter 8 years of attacks from the media. The GOP party itself also failed to counter the attacks.
If the conservative movement is to be resurrected, it will be due to someone in the party successfully steering the mainstream media into more of an objective posture.
So you don't think the actions of the GOP while in the White House and while in control of Congress didn't have anything to do with it? It was all bad press?