Right now, almost every Republican Congressperson is afraid of crossing Donald Trump for fear of being primaried (my spell checker is going crazy). After Super Tuesday, enough Republican Congresspersons will no longer be concerned about someone who is supported by Trump, opposing them on the ballot.
In fact, I think it's possible Trump will be losing power with most of his present Senate and Congressional supporters, because as we get closer to the November election, the reality of Trump's legal problems will become a growing weight on the entire Republican Party, not to mention the abortion issue.
The next questions to be answered, how much of Donald Trump's power will linger after he is defeated in November?