The venal, greedy, incompetent democrats have handed republicans a gift - an almost iron clad guarantee that voters will be ready to boot democrats out of office in 2014 as a reaction to Obamacare and the lies and deceit democrats used to push it on the country.
So what do republican “leaders” do with this gift?
They spend their time making war on fellow republicans, especially conservatives without whom they will never win another election.
Someone made a good point earlier - they're probably terrified that the oncoming "wave" election is going to result in a large enough conservative (as opposed to Republican) delegation to disrupt the "business as usual" model that's been so comfortable and profitable for them.
SO, it's all hands on deck to blunt any conservative surge in the primaries, and then ride the lesser wave to (at most) a narrow control of both chambers. Honestly, I doubt they'd care if they stayed as the minority party in the Senate, as long as the apple cart isn't disrupted.