I would wait until the ny state has his tax returns and begin the impeachment progress. There is a good reason why he didn't publish before the election. It tells where his eggs are in the basket. The big thing to check for is money laundering, like how much cash was going through his hotels.... Also wondering if he owned any electronic voting stations....
As for the majority of the senate being republican, the senate is coming up for re-election. Each republican senator will have to ask himself/herself did Trump willing break the law, if so was it for Trump's own benifit? The fact that you are going outside political lines of your country. The fact that he didn't do this right after he was elected, only after Biden put his name in for the Democrats did Trump start his witch-hunt.
The problem I see with Trump is he surrounds himself with yes men..... Go back and read the press talk about republicans who did not want to be in the presidential team; ever wonder why.... What I do know for sure is that the American people did not get the best people to advise the President, mainly because I think that they did not want to say every meeting, I thank you Mr President for the opportunity you have given me etc.... etc... you know like that televised cabinet meeting where everyone around the table was sucking up to him in the worst possible way.....