He has plenty of time and energy and Twitter followers who want to hear what he has to say.
And considering that one of his enemies is the media itself, he needs to keep getting his story--the truth--out there.
The problem is that voters can only focus on a few things at a time and Trump is allowing Ryan and the GOPe to put him on the defensive. He is so busy fighting them, he isn’t fighting Hillary and she may end up winning because R turnout is suppressed — one of her strategies.