He got out of Atlantic City at the right time, didn't he? He likes to win, and winning can be defined as getting out at a high point and not being there for the big loss. And — as the post title jogs you to think — Trump likes to be flexible. He believes in surprises.
So I'd like to assume that he'd consider the ploy of dropping out and letting someone else take the race to the finish line. The question I want to focus on is: Where is the high point? It's not right now, obviously. He shouldn't be bullied and humiliated out of the race. So where, down the road, can we see a high?
He should think about how to do the most damage to Hillary and then jumping out and making it irrelevant that he was the one who did the damage. Someone else — somebody clean — will be slotted in, and then how can Hillary fight back? She'll have to redo everything and deal with this new person, this Mr. Clean — maybe Pence, but how about Scott Walker? Pick someone hard to attack, someone who'll look just completely normal. That would flummox her after she'd premised so much of her campaign on the idea that she's normal compared to Trump and normal is what we want. If not Trump was so desirable in August, then not Hillary (and not Trump) could be the relief we're all dying for by October.
I'd say he should stay in through at least the first debate. Only he will know that he's planning or considering dropping out. She will waste effort attacking him, her ultimate non-opponent. And he can be as cruel as he thinks could be effective — and as showy and outrageous as will serve his interest going forward in his media career. He's been attacking the media, but he is media, and he will be media in the future (unless he's stuck being President, slogging away in that humble abode, the White House, and getting brutalized by absolutely everyone for 4 years).
What freedom he has right now! What power!