it won't be Obama That where the oddsmakers are, but I have reason to believe the "darkhorse" will find his way to the "winner's circle", in this case, the big house.
Time will tell. I tend to think that Trump doesn't want to go after Obama. He can drain the swamp by making public examples of a few very high profile fish while leaving the biggest one alone and not taking on the incredible death match fight that going after Obama would trigger. Same with Hillary, for that matter. He will tweet about her to point out hypocrisy but he won't instruct anyone to actually prosecute her.
Brennan, Clapper, and McCabe all wearing prison stripes would make the bureaucrats in the deep state flee like rats. Or at least dial their activism waaaaaaay down.