Um...
Yeah. Kinda looks like we've got confirmation already. I honestly thought it would take longer, and be more difficult, but by the end of the day yesterday, there were so many different confirmations that Trump was furious with Comey over Russia that while I don't know how to assess the current state of evidence in terms of legal thresholds, we've crossed the line of constitutional crisis, in my opinion, if Congress continues to do nothing, as is likely. Firing the Director of the FBI in retaliation of, or in order to block an ongoing investigation is obstruction of justice.
So why won't Congress act? The simplistic answer is that a Republican majority doesn't want to hurt a Republican President. When (the) Watergate broke, the whole Republican Party suffered in the 1974 midterm election, and it probably helped Carter in '76. The party's reputation took a hit that lasted for years. Yes, Trump is crooked, but if Republicans help cover up whatever he has done, they may be able to preserve something of the party's reputation by preventing the worst from happening. Here's the problem, though. It is risky for any one Republican to participate.
This kind of thing gets into what we call, in social science, "the collective action problem," coming from Mancur Olson's The Logic of Collective Action. There is some "public good," from which everyone benefits, but which requires lots of people to contribute. Any one person's contribution is basically irrelevant. Therefore, it is irrational for any one person to contribute, so nobody contributes, so the good doesn't get provided. That's the collective action problem.
In this case, we can think of the wagons circled around Trump as a kind of collective good. The Republican Party needs everyone, or at least a lot of Republicans, to act as though Trump is no more corrupt than any other politician and that any criticism is just partisan smoke being blown. That way, the party can weather most storms by convincing the uninformed audience that there's nothing to see here, folks, move along.
The problem is that this might be a storm too big to weather, and if so, the benefit of being one of the Republicans who doesn't rally around Trump could be big. There are real incentives here for individual Republicans to not join the wagon circle. Collective action problem...
If Trump is compromised by Russia, and he did fire the FBI director for looking into the connections, then this is, by far, the biggest scandal in US history, and any Republican who helps cover it up may go down with Trump. That could be a party-destroying scandal. The Republicans who stand against the party could be the ones who weather the storm. If Trump is doomed, on the other hand, the party's best chance to survive is to turn on him completely, knowing that it will just lose the next couple of elections and take some time to recover, as it did after Nixon.
Some Republicans are breaking from the party and calling for more serious investigations here. I wonder how this shakes out, but it is kind of interesting that more aren't turning on Trump yet. More to come...