Maddow said on the Tonight Show with Jimmy Fallon:
It's actually genius. I don't think he's a dumb guy. I don't think he's playing a dumb game here. . . .
If he was going to say at [the first] debate, "No, no, no — I'll never run as an independent — I'll only run as a Republican," he loses all his leverage. Then he just is one of the other Republicans.
But if he says, "No, you guys be nice to me; otherwise, I'm going to jump in as an independent," thereby guaranteeing that Hillary Clinton will be the next president, what does that mean? That means if he doesn't do that, the Republicans owe him forever. And if he does do that, Hillary Clinton becomes president, and she owes him forever! Nice!
So, . . . he will never have more power than he does right now. Because either way this goes, whether he runs as an independent or he doesn’t, half of the country’s political infrastructure is going to owe him for the rest of their lives. That is the art of the deal!
I got this from Mediaite, which seriously misquotes Maddow as saying either the Republican or Democratic party will "own him" (instead of "owe him"), which would suggest almost the opposite of what she really said.