5 Republican defections: Brown, Collins, Snowe, Kirk and Murkowski (thank you Alaska!). The GOP would need to replace an additional 15 Dems with conservatives (and/or replace a number of the RINOs) to have even a marginally conservative caucus and about 25 to have a solid conservative majority. That’s how far the GOP Senate caucus is from being a truly conservative caucus.
Collins and Snowe aren’t really Republicans. Rather, they are old biddies up to senile meanness.