We’ve said for months that Iowa and New Hampshire are two of the best states for Sanders demographically. You can see why in the entrance poll taken in Iowa. Sanders won very liberal voters over Clinton by 19 percentage points, but he lost self-identified somewhat liberals and moderates to Clinton by 6 percentage points and 23 percentage points, respectively. That’s bad for Sanders because even though 68 percent of Iowa Democratic caucus-goers identified as liberal this year, only 47 percent of Democratic primary voters nationwide did so in 2008. We’ll need to see if Sanders can do better in a state that is more moderate than Iowa before thinking he can win the nomination.

Iowa and New Hampshire also lack nonwhite voters, who form a huge part of the Democratic base. Can Sanders win over some of these voters? Clinton has held a lead among nonwhites of nearly 40 percentage points in national polls. In Nevada, which votes after the New Hampshire primary, the electorate for the Democratic caucuses in 2008 was 15 percent Hispanic and 15 percent black. After Nevada comes South Carolina, where a majority of Democratic voters will be black. Our polls-only forecast in South Carolina gives Clinton a 94 percent chance to win, and our polls-plus forecast gives her a 96 percent chance to win.