Third-most likely 45th President?

[Figueira]

If someone from the future tells you that neither Hillary Clinton nor Donald Trump is the next President, who could it possibly be?

[mencken]

Tim Kaine

[sobo]

Tim Kaine. Far more likley that either Clinton or Trump dies or is incapacitated over the next three months than that some crazy EC scenario throws the election to someone else, and Clinton's more likely to win than Trump, so...

[HisGrace]

Odds wise it may be Biden, if Obama were to get assassinated or suddenly die for some reason. He's in good health but it seems like the stress of the presidency could cause a heart attack in a lot of people.

Otherwise I would say Pence or Ryan in the slim chance that the election goes to Congress and there's so  much gridlock that they can't elect anyone (more likely than them choosing McMullin). It's Pence if he gets elected VP in the Senate and Ryan if there's gridlock in both chambers.