For Trump to have a decent shot at winning, three things must happen:
1) Someone has to keep a muzzle on him so he doesn't say more dumb things;
2) He is going to have to try to woo/appease the concerns of the party as a whole, including picking a ticket-balancing VP (like Martinez) to help him with that.
3) Hillary, or at least one or more of her top aides, must get indicted.
If he can unite the party and present himself as a less-scary than expected alternative to Hillary (which was Reagan's big trick), and the emails end up having a sting, we might pull it off.
Hillery's girl friend Huma will probably be thrown to the wolves as a parting insult by Obama to get the FBI to leave Hillery alone.