The 2020 Democratic primary so far has featured an interesting racial breakdown: The party’s black voters have been decidedly with one candidate (former Vice President Joe Biden), its Hispanic voters have been leaning toward another (Sen. Bernie Sanders), and white voters have been more evenly divided between the two. We’ll need more data, polling and election results to know how that’s changed in the wake of Biden’s romp on Super Tuesday — today’s elections will provide some answers — but it’s worth asking why voters split the way they have so far.

Biden has won black voters in nine of the 10 states where exit polls got enough black respondents to offer information about how they voted (he and Sanders were effectively tied in Minnesota). And in nine of those 10 states (all but Massachusetts), Biden won a lower share of white voters than black voters. We should emphasize that Biden was much more popular among black voters in the South (getting between 58 and 72 percent of the black vote in those states), while he won only around a third of black voters in California and Massachusetts. Sanders, meanwhile, finished ahead of Biden among Hispanic voters in five of the seven states with exit poll results for the group, including delegate-rich Texas and California, though votes are still being counted there. Sanders won a higher share of the Hispanic vote than the white vote in all seven. (National polls also generally show Biden stronger with black voters, Sanders with Latino voters.)

White voters, meanwhile, have been pretty equally split. Biden beat Sanders among white voters in eight of the 15 states for which we have exit poll data, Sanders beat Biden in four, and they were effectively tied in three. (Sanders was the most popular candidate among Asian Americans in California, the only state where we have vote breakdowns for Asian voters.)

What explains this dynamic?

I think the strongest explanation is that when Biden entered the race in April 2019, he was already polling well with black Democrats, likely because of his close ties to former President Barack Obama. In other words, it might be less that Biden’s 2020 campaign has been particularly effective in wooing black voters (or that other candidates were particularly ineffective) and more that Biden started off the race with this advantage and did not squander it. No candidate had such a huge lead with Latino or white voters at the start of the campaign. So those groups were more up for grabs, and Sanders, as the second-most-successful candidate in this race, made gains with those racial and ethnic groups. Sanders’s campaign worked hard to organize Latino voters in Nevada and California in particular, but it also aggressively courted black voters in South Carolina in the 2016 cycle and in the run-up to this year’s primary to little avail, facing two candidates (Biden in 2020 and Hillary Clinton in 2016) who entered their races with strong black support.

But that’s just one theory. Biden’s strength with black Democrats and Sanders’s relative strength with Latino Democrats is also probably related to …

Ideology and political attitudes

In general, black voters tend to back establishment candidates, like Biden, and are less likely than Latino or white Democrats to describe their ideology as liberal. So perhaps black voters, particularly older ones and those in the South, would never have embraced a self-proclaimed Democratic socialist like Sanders.

But we should not overstate this ideological explanation. Black voters throughout the process have talked about being pragmatic and choosing someone electable to take on President Trump. That made some of them hesitant to embrace, in particular, Sen. Kamala Harris — many worried that America wasn’t ready to elect a woman of color as president. But that didn’t lead black voters to support other white men, like ex-Rep. Beto O’Rourke or former South Bend, Indiana, Mayor Pete Buttigieg.

Indeed, candidates like Buttigieg and Sen. Amy Klobuchar never gained much traction with black voters even though they, like Biden, ran on center-left policy platforms. Harris and fellow Sen. Cory Booker ran slightly left of Biden but have similar politics to Obama, and they also struggled to win black support with Biden in the race. Polls suggest black voters have favorable views of Sanders now and did in 2016 as well, when he lost the black vote overwhelmingly to Clinton.

Remember that Obama himself, running as the outsider-y, left candidate against Clinton, overwhelmingly won black support in 2008, suggesting that black voters don’t always align with the more centrist, establishment candidate.

All of that makes me think some of the story here is simply that Biden is just popular with black voters — particularly older black voters and black voters in the South. And that popularity is probably a result of Biden’s personality and history as much or more than his policy stands or ideological positioning.

Age

Sanders does better among younger voters — it’s probably the defining characteristic of his coalition. Biden does better with older voters. And as groups, relative to the electorate overall, Latino voters tend to skew young and black voters tend to skew old. The exit polls from the Super Tuesday states for which data is available suggest that about half of Latino voters in those races were under age 45, compared to only 33 percent of white voters and 29 percent of black voters.

That said, we know the racial/ethnic split is not simply a product of age. Biden won every age cohort of black voters except those under age 30, and Sanders won every age cohort among Hispanics except those over 60, according to the exit polls. So what may be going on here is that younger Latino voters and older black voters in particular were more enthusiastic about their candidates and more motivated to turn out to vote.

Immigration policy

The high number of deportations during Obama’s tenure in office may mean that having served as his vice president isn’t much of a credential to Latino voters.

“Biden and Sanders both can attribute some of their success with black and Latino voters to Obama,” said Menlo College’s Melissa Michelson, an expert on identity and politics, told me. She argued that the former president was helping Biden with African Americans but potentially hurting him with Latinos.

I’m leery of delving much deeper into the political attitudes of two racial/ethinic groups in a short piece, so I will stop there. There is not necessarily any reason to assume that black and Latino Democrats would support the same candidate, so we shouldn’t treat the fact that they’re not backing the same person as some huge development. This difference in racial support is not totally unprecedented — in 2008, black voters aligned with Obama, Latino voters with Clinton. (Clinton won both groups against Sanders four years ago.) But the differences in 2008 were easier to explain, since Obama is black.

Moreover, many of the states with large black populations that have voted so far are in the South, and those with large Latino populations are mainly in the West, so these results may look different as more states vote. Also, there’s no guarantee that this dynamic will persist — Biden’s status as the clear front-runner now may push Latino voters more into his camp.

In any case, watch these numbers in upcoming states — including today’s contests. Perhaps Sanders will fade and his strong numbers with Latino voters early in the process won’t add up to any kind of real coalition. Alternatively, we could be seeing the emergence of something interesting: Latinos mobilizing behind a single candidate in the Democratic primaries the way African Americans did in the 2008, 2016 and now 2020 primaries. We haven’t really seen that before.