Candidate Trump needs to be belligerent and defiant. Defendant Trump needs to STFU.
The problem is those two things are in competition. So he has to say, Russia, Russia, Russia as candidate Trump, but that isn't a relevant or useful argument for defendant Trump. He has to say, "I'm allowed to do this thing" as candidate Trump, but as defendant Trump, I'm allowed to break the law is not a defense.
His only hope is to delay. If he goes to trial on anything, defendant Trump loses. If he can hold out, then candidate Trump will win.
This is his bet. He wins and it all goes away and the US is ruled by a guy who believes he can get away with anything.