Anyone holding their breath hoping that the Republicans will save us from Trump and his pack of absolutely awful aides and secretaries should just stop. Yes, there are two ways that the GOP could save us from catastrophe: encouraging the electors to vote for someone else or to impeach Trump early in his term. Putting aside the potential dangers to democracy and our institutions that the first option might pose (I have no idea which is worse--electoral college being faithless or Trump taking office), I just want to focus on the Republican dilemma.
Yes, there is a mutual hostage relationship between the Republican Party and Trump. Paul Ryan could facilitate impeachment, with real grounds existing (emoulements, anyone?). But Trump can also call out his supporters, the hard right, to vote against GOP candidates or stay home. Either way, the GOP could face yuge defeat, bigly, if a significant chunk of its base didn't vote for them in the next set of elections. Any effort by the GOP to dethrone Trump would be tremendously costly for the party. We saw during the primaries that the party had no taste for this, as the candidates avoided attacking Trump since they wanted his supporters.
In games of chicken, single actors, such as Trump, have advantages against collective actors, such as the Republican Party. Trump does not have to coordinate to stay on the path of confrontation, while the GOP would have to do so. Efforts to coordinate against Trump failed during the primaries, so why expect them to succeed now that he has far more power and poses a greater threat to the party? A second set of advantages involves risk acceptance or aversion. Trump, if impeached successfully, gets to go back to Trump Tower and not have to do the heavy lifting required of the Presidency. He really has nothing to lose in a fight with the GOP. The GOP? Again, it could be ripped apart in a confrontation.
So, no, not even direct proof of Trump working with Russia would cause the GOP to rise up one way or another. The GOP is stuck with Trump for four years. Which means the rest of us are, too. We can focus on resistance, but we have to be clear that this is the guy we are stuck with. Sucks, but there it is, and no re-arguing the fall campaign is going to change things. Maybe we ought to focus on what we can do to thwart Trump's appointees and Trump himself, rather than imagining what could have been or what the GOP might do.
But what do I know? I am just an international relations scholar thinking about how mutual assured destruction applies to the Republican Party.