Let’s play a game I’m calling “Guess That 2020 Candidate.” The person I’m thinking of is a fresh face who would make history if elected president. They have ties to Harvard University and are known for giving thoughtful, sometimes wonky answers to questions. They hail from the middle of the country, which they play up on the stump. They’re a trendy choice among cosmopolitan elites, but they face a real challenge in diversifying their coalition.

It’s a trick question, of course: That description can apply to either South Bend, Indiana, Mayor Pete Buttigieg or Sen. Elizabeth Warren. Given everything the two have in common, it seems like they would be competing for the same “lane” of Democratic voters — which implies only one can emerge as the winner of what I’ll call the “ivory-tower primary.”

Except their supporters aren’t exactly alike. At least, not anymore. And that’s because highly educated white Democrats — like every demographic — aren’t a uniform voting bloc.

I dove into the crosstabs of some recent polls to see how much Buttigieg and Warren are truly relying on the same type of voter. And their supporters do have some obvious similarities. For example, the candidates’ bases are predominantly white — and they especially struggle among black voters. Check out their support by race in recent national polls of the Democratic primary:

Buttigieg and Warren do better with white voters Support for Pete Buttigieg and Elizabeth Warren by race in recent national polls of the Democratic primary Buttigieg Support Pollster White Black Hispanic McLaughlin 4% 1% 6% Quinnipiac 13 4 — Economist/YouGov 10 1 5 The Hill/HarrisX 8 4 4 Emerson College 11 1 0 Morning Consult 8 1 4 Reuters/Ipsos 5 0 5 SurveyUSA 8 2 1 ScottRasmussen.com/HarrisX 6 1 3 Average 8 2 3 Warren Support Pollster White Black Hispanic McLaughlin 21% 9% 14% Quinnipiac 33 20 — Economist/YouGov 24 12 22 The Hill/HarrisX 21 16 14 Emerson College 23 11 27 Morning Consult 25 12 17 Reuters/Ipsos 19 7 13 SurveyUSA 25 14 22 ScottRasmussen.com/HarrisX 22 11 13 Average 24 13 18 Data set is the nine polls that include crosstabs for white and black voters among the 10 most recent national polls of the Democratic primary, as of Oct. 28, 2019. Source: Polls

On average, Buttigieg pulls 6 percent of the vote overall in those polls, but 8 percent of the white vote. And Warren garners 20 percent of the vote overall, but 24 percent of the white vote. By contrast, every poll agrees that black voters are less likely to support Buttigieg and Warren than Democrats do overall. The signal is fuzzier among Hispanic voters (the occasional poll does show Buttigieg and Warren doing particularly well there), but on average, the two Democrats are also less popular with this demographic than the party overall.

The polls also indicate that both Buttigieg’s and Warren’s bases are disproportionately college-educated. While we don’t have a table for you here, most of the polls analyzed above agree that Buttigieg’s and Warren’s numbers get better as you go higher up the ladder of educational attainment. For example, in the CNN/SSRS poll, Warren registered at 25 percent support among college graduates vs. 14 percent among non-college graduates, while Buttigieg registered at 7 percent among college graduates vs. 4 percent among non-college graduates.

But there is at least one important distinction between Buttigieg’s and Warren’s supporters. While both candidates have predominantly white, college-educated bases, Warren’s is more clearly liberal, while Buttigieg’s is more ideologically diverse.

Buttigieg’s base isn’t as as left-leaning as Warren’s Support for Pete Buttigieg and Elizabeth Warren by ideology in recent national polls of the Democratic primary Buttigieg Support Pollster Very Liberal Somewhat Liberal Moderate The Hill/HarrisX 5% 7% 5% Emerson College 6 7 6 Morning Consult 5 8 6 SurveyUSA 4 7 6 ScottRasmussen.com/HarrisX 6 3 5 Average 5 6 6 Warren Support Pollster Very Liberal Somewhat Liberal Moderate The Hill/HarrisX 29% 22% 14% Emerson College 35 18 18 Morning Consult 31 25 16 SurveyUSA 27 30 13 ScottRasmussen.com/HarrisX 17 25 16 Average 28 24 15 Data set is the five polls that include crosstabs for very liberal, somewhat liberal and moderate voters among the 10 most recent national polls of the Democratic primary, as of Oct. 28, 2019. Source: Polls

It’s clear from the polls that liberal Democrats — and specifically very liberal Democrats — are Warren’s bread and butter. Although she averages 20 percent overall support in the polls in the table, she averages 24 percent among somewhat liberal respondents and 28 percent among very liberal ones. But Buttigieg doesn’t seem to have an obvious ideological base. For example, the latest Quinnipiac poll says Buttigieg’s support is about equally strong among moderate/conservative voters and somewhat liberal voters, but notably lower with very liberal voters. But CNN/SSRS finds higher Buttigieg support among liberal respondents than moderate and conservative ones.

Notably, back in April, when Buttigieg raised his profile and enjoyed a modest polling bump, the ideology of Buttigieg supporters was less ambiguous: He was appealing primarily to liberal Democrats. Per a Monmouth poll at the time, he was at 12 percent among liberal respondents but only 5 percent among moderate or conservative ones. In CNN/SSRS’s April poll, he was at 11 percent among liberals and just 4 percent among moderates.

In other words, Buttigieg’s base in April looked more like Warren’s does today. What caused them to diverge? One theory is that Buttigieg himself has tacked toward the center. On the campaign trail, he has deemphasized his plans to overhaul government institutions and attacked Warren for being evasive on how she will pay for her “Medicare for All” proposal. Instead, his campaign is promising “a plan that works for all of us,” which may very well be resonating with the more consensus-oriented wing of the party — and alienating true believers on the left.

But it could also be that Buttigieg’s rhetorical pivot was dictated by a new political reality for him — that Warren, who has risen steadily in the polls since April, is now dominant among the white, liberal, college-educated voters who gave Buttigieg his first surge. If so, Buttigieg’s message may be changing in response to the polls — not the other way around.

Regardless of whether the chicken or the egg came first, daylight opening up between the Buttigieg and Warren bases has some important implications. First, if they are no longer competing for the exact same pool of voters, it’s possible that the primary could come down to Buttigieg and Warren (and probably a third candidate whose base is nonwhite voters, if Buttigieg and Warren don’t improve on that score).

Second, if Buttigieg’s base continues to shift toward the middle, he may end up grateful to be in the moderate “lane”; according to the 2016 Cooperative Congressional Election Study, half (51 percent) of Democratic primary voters are actually moderate or conservative, not progressive.

And finally, more broadly, the subtle shift in Buttigieg’s supporters since April suggests that candidate coalitions can be malleable. Just because a candidate’s base is a certain type of voter today doesn’t mean he’s stuck with that wing of the party for the rest of the race. Political analysts — hi! — would do well to remember that.