The face-off between Senators Bernie Sanders and Elizabeth Warren has been billed as the marquee matchup of Tuesday’s debate. The two progressive standard-bearers share much in common in terms of policy, and at first glance they seem similarly situated in the polls: They each hold around 15 percent in the most recent surveys, placing them in a rough tie for second place behind Joseph R. Biden Jr. But there’s more divergence in their supporters than one might think.
Ms. Warren draws from a whiter, more affluent and better-educated group of Democrats; Mr. Sanders’s supporters, on the other hand, are younger, more diverse, less affluent and less likely to have graduated from college.
And while Ms. Warren’s gains over the last several months might seem to have come at the expense of Mr. Sanders, it is not so clear whether the two candidates are competing for the same group of voters. Polls show that Senator Kamala Harris, not Mr. Sanders, is the second choice for a plurality of Ms. Warren’s supporters, according to Morning Consult polls. Perhaps surprisingly, Mr. Biden is the second choice for a plurality of Mr. Sanders’s supporters. Should either falter, it is not obvious that the other stands to make outsize gains, at least in the polls.
For now, Mr. Sanders and Ms. Warren trail Mr. Biden in no small part because of Mr. Biden’s support among older, more moderate and black voters. Many of the other candidates onstage Tuesday have similar challenges.
Pete Buttigieg, for instance, draws from a particularly well-educated and white group of Democrats. It is enough to give him around 6 percent of Democrats nationwide, and a chance to compete in Iowa and New Hampshire, where voters are relatively white. But it will be difficult for him, or anyone, to contend for the nomination without broader support among nonwhite Democrats.