That would be great! Can't you just see the Sanders and Warren folks going crazy as wicked Hillary swoops in on her broom and tries to steal another election from the Socialist wing of the party? I don't think they would take it lying down this time, even if it meant assuring Trump is reelected they would likely run a 3rd party candidate against her.
Hillary is either blowing smoke, or she’s reached a new stage of delusion.
It’s really hard to beat an incumbent president - especially if that president is widely perceived to be successful, and has high approval ratings. Trump has both.
Perhaps someone could beat him, but that person hasn’t yet appeared. It’s certainly not Hillary.