The interesting thing to me about the fallout from all of this is that all the prominent GOP figures have had one of two responses:
1) VERY strident defenses of Trump's handling of Ukraine. To the point of refusing to acknowledge that it's even possible for him to have done something wrong. (the approach you see from NPC and Catchall here); or
2) Total Silence
Camp 1 is tribal epistemology. The truth value of any piece of information is wholly defined by how much it benefits the tribe. Anything unhelpful is a "lie." These people are unreachable. At this point they are not even defending Trump as much as they are defending their previous defense of Trump. They are too ideologically pre-committed to change course.
Trump's fate is going to be determined by group #2. And the more pressure put on them, the more likely we are to finally have something happen that has quite obviously needed to happen for going on three years now - someone holding Trump truly accountable for the things he says and does.