What stupid shyt are you referring to? Only gaffe I can see so far is calling out a baby at a town hall. Everything else has been in response to attacks.
If trump wants to win, it's simple. He needs to keep his mouth shut when provoked. That whole Kahn situation was a no win from the get go. Just be humble and thank their son for their service. That's all he had to do. His thin skin and constant need to defend himself is going to be his downfall.