2016- quite a few candidates

[P. Clodius Pulcher did nothing wrong]

Bernie in a landslide.  You basically have 3 Republicans running against him, 4 if you add Johnson (Jill Stein by the way wouldn't have run if Bernie was the Democratic nominee).

Regardless of what some people believe, Hillary Clinton is still a liberal Democrat, even if she isn't as liberal as some would have hoped.
It would likely end up with Sanders, Clinton, and Trump as the top three, with the House electing Trump. And since we're going out on limbs here, I predict riots.