...that they were all punked in one form or another by Trump, meaning that one incentive is simple revenge, coupled with a dogged attempt at restoring their own reputations. A second incentive is their own political career/viability, which would be annihilated if Trump were to become president again. A third incentive is that they are not MAGA, meaning they are political opponents of Trump in the same sense that Joe Biden and Nancy Pelosi are political opponents of Trump -- i.e., on ideological grounds -- making their criticism as suspect as criticism from a Democrat.

Your hyperpartisan lens only allows you to view the world in Democrat vs. Republican terms, so you can't see the real world where the dynamic is actually DC vs. America. Hence, you can't fathom why a "Republican" could possibly have an incentive to criticize Trump for self-preservation reasons despite establishment Republicans criticizing and trying to undermine Trump since he came on the scene eight years ago.