The GOP committed suicide when it screwed over its voting based by promising it would take Obama on once it controlled Congress. Once it had a majority, it rolled over and played dead and did everything Obama wanted. The GOP was screwed from then on in terms of credibility and conservative loyalty.
Of course Senator McConnell is to blame that he did not insist on super majority requirement like dingy Harry Reid did.
The LEADERSHIP rolled over and played dead. There were conservatives fighting the fight, but they had to fight BOTH, the Democrats and the Vichy Republicans.