Nate Silver @NateSilver538
The path could easily be straight down—he's got big issues and I don't think any of the Democrats, including Biden, has more than like a 1-in-4 or 1-in-5 chance, so you're always smart to bet against any of them at even odds. But it'd be down from a much higher perch than Jeb. — PolitiTweet.org