[cogitator]

Let's see how much they value their political careers.

Senate races have become much closer than House races in recent years (due to incumbent-protection districts). How many GOP senators do you want to lose before the Dems control the Senate again? Even if you have moderates like Chafee, Collins, and Snowe, they do mean the the GOP controls the Senate, and that means a lot of power over committee hearings, floor agenda, etc. It may not seem so recently, but returning the Senate to the Dems would really bollix the works.

[Jokelahoma]

Well that's sort of my point, really. Are they willing to risk getting voted out of office by working against their constituency? If so, then their constituency can support a conservative in the primaries. We tend to forget that just because they are in office with an (R) after their name doesn't mean we can't find someone better.