Transcript for If Joe Biden wins Iowa, 'he's off to the races': Nate Silver
He will do everything he can possibly to bait me and, by the way, if I'm not your nominee, if I were to drop dead tomorrow, guess what? You think he's not going to go after and lie about and misrepresent and deal in the dirt with whomever the candidate is. He'll come up with something in their life. The difference with me I have taken it now for eight months and I'm still winning. There's Joe Biden, he leads the national polls and the new primary model by fivethirtyeight. But a brand-new poll from the Des Moines register puts Bernie Sanders on top for the first time. So, is Joe Biden really the favorite for the nomination? We asked Nate silver, do you buy that? So we just came out with the forecast of the primaries at fivethirtyeight and we're pretty darn excited about it. Our model literally simulates the entire process from Iowa in February to the Virgin Islands in June. The question is, can some candidate hit the magic number of delegates? Our forecast tells Joe Biden the most likely person to win the majority of delegates. Let's break that down. Say, Biden wins Iowa for example, if he does he's off to the races. If Bernie Sanders or Elizabeth Warren might fight back in new Hampshire, it could start to look a lot like Hillary Clinton versus Bernie in 2016. But Biden's polling in Iowa isn't that great. He's basically in a four-way tie there. Which means there are three other people who could win. What happens if Biden loses Iowa? Then his chances fall to 20%. He could fight back in more diverse states like Nevada and South Carolina. So sorting through all these scenarios our model gives Biden about a 40% chance of winning a majority of delegates. A favorite means over 50% and Biden is winning less half the time in our models. If he doesn't win, who else might? Bernie Sanders has the next best chance in 22% of majority. He has plenty of strength in Iowa and New Hampshire. Warren comes next with a 12% chance of winning the majority. Then there's Pete buttigieg, his chances are at 10%. There's still one big if. What if no one wins a majority because the early states produce three or four different winners. That's a real possibility, too. In fact, our model has about a 15% chance of doing no majority at all. If that's the case we're looking at a contested convention. Sure it sounds a little crazy. But until people actually start voting our advice is not to rule anything out. Good advice. Roundtable is coming up. Plus, president's national security adviser Robert o'brien.
This transcript has been automatically generated and may not be 100% accurate.