The Senate Conservative Rep. Com., to my knowledge, have NOT been totally supportive of incumbents. That is the group Senator DeMint used to chair. I was on the mailing list for them and they did not support incumbents unless they were conservative ones. There are other groups int he Senate that sound similar, but the group DeMint lead was strictly for conservatives.
DeMint is a big backer of Lindsey Graham, or has he switched on that? That’s why I don’t pay much attention to DeMint.