Donald Trump is on the verge of locking in a racial deficit within the Republican Party that GOP officials won’t overcome for at least a generation, as he systematically alienates Latinos, African-Americans and anyone worried about the powerful undercurrent of white anger on display at his rallies.

But as his racial gaffes have claimed the spotlight, far less appreciated is what has been happening in the opposing party. Democrats face their own racial split that could haunt the party well into the future if it isn’t handled properly now.

Though it might offend his uber-progressive supporters to hear this, the Sanders insurgency is largely a white revolution. All the talk about Sanders representing the future of the Democratic Party because of his overwhelming popularity among young people leaves out an important caveat: He couldn’t persuade minority voters to sign on. In many ways a Sanders victory, propelled by the least diverse states in the nation, would have been a step backward in American race relations. Now that Hillary Clinton has laid claim convincingly to the nomination with decisive wins in California and New Jersey, the party—and Bernie’s supporters—are at a crossroads. If they insist on maintaining their purist divide from Clinton, they will create a rift in the party that’s not just ideological, but racial.

Barring an asteroid strike that extinguishes life on Earth, the American electorate will be much more diverse in coming elections than it is today, especially the portion of it that Democrats plan to rely on. There are now more non-white than white babies being born every year, and the under-18 crowd is close to reaching majority-minority status as well. That’s the Democrats’ greatest potential strength, which grows only more pronounced the closer Trump comes to being officially named the GOP nominee.

But it’s also a fault line. Sanders coming from seemingly nowhere to seriously challenge Clinton while drawing historically large and enthusiastic crowds has soaked up much of the attention in the Democratic race, making it feel as though he’s hit a chord that resonates throughout the party. But his brand of idealism has been rejected by the majority of minority voters—Clinton won every contest with at least a 10 percent black population, except Michigan, and each state where Latinos make up at least 10 percent of eligible voters, except Colorado, according to Harry Enten of FiveThirtyEight.com. On top of that, they have been mocked by some Sanders supporters for supposedly “voting against their self-interest” because they refuse to believe a political revolution is at hand. That has been particularly galling to black voters who had to endure claims from conservatives in 2008 that they were voting for Barack Obama only because of race—even though they had spent their entire adult lives voting mostly for white presidential candidates. Now their preference for Clinton’s brand of pragmatism, something they’ve seen result in real progress time and again, is being questioned as well, this time by fellow Democrats.

Read any number of pieces analyzing the Democratic race and it becomes clear just how unaware the party is about the racial land mines. They present data showing a racial divide within Democratic ranks but discount it, displaying a kind of wishful thinking indicative of those who don’t fully appreciate the power of race to shape relationships.

Jonathan Chait came closest to recognizing the looming problem in a piece that was published in early April, detailing why black voters are pragmatists:

“That refusal to accept the necessity of compromise in a winner-take-all two-party system (and an electorate in which conservatives still outnumber liberals) is characteristic of a certain idealistic style of left-wing politics. Its conception of voting as an act of performative virtue has largely confined itself to white left-wing politics, because it is at odds with the political tradition of a community that has always viewed political compromise as a practical necessity. The expectation that a politician should agree with you on everything is the ultimate expression of privilege.”

As perceptive as that analysis is, it fails to fully account for the racial divide. The tensions within the party aren’t only about purity vs. pragmatism; they have to do with how life is lived and perceived. And though millennials aren’t stuck in the mud on race the way the generations that came before them can be—in large part because they don’t have scars from the 20^th century’s contentious civil rights battles—they are not ushering the country into a post-racial age as some have claimed.

People of color, like their white Democratic counterparts, may also want a revolution and more rapid progress than the halting kind that comes with pragmatism, but they’ve time and again seen incremental change improve their lives. That’s why they embrace Martin Luther King Jr. without question while revering Malcolm X from a distance. That’s why they are much more enthusiastic about the Affordable Care Act—which has helped minority Americans the most— than white progressives who have either been lukewarm or, in some cases, even hostile to health reform because they don’t believe it was radical enough.

Minority voters are more likely than white Democratic voters to giddily give Obama credit for an economic recovery that has shaved the unemployment rate in half, produced the lowest level of jobless claims since the ‘70s, and an unprecedented monthly job creation streak that has lasted more than six years, all coming on the heels of the worst economic downturn since the Great Depression. And he got Osama bin Laden, saved the domestic auto industry, ushered through the largest economic stimulus in history—one derisively dismissed as too small by many liberals—and the first significant Wall Street reform in a generation, while advancing gay rights like no president before him despite the initial reluctance by his numerous religious black voters to embrace same sex marriage.

Why? Because many white Democratic voters missed the sentiment shared among black Obama voters in 2008 that, once again, the “first black” was being handed a seemingly impossible task—two ground wars, a collapsing economy, a record deficit—and if he wasn’t able to perform a miracle, it would not only be his failure, but that of black people in general. To downplay what he has been able to achieve despite the obstacles, which also included an unprecedented level of obstruction from the GOP, confirms a fear shared by many people of color—Democratic or otherwise—that no matter what they achieve, it will never be enough. Sanders and Susan Sarandon may sincerely believe things are so awful only a revolution can heal the country’s ills. But their overwrought rhetoric, and no more than lukewarm support of Obama’s accomplishments, taps into that deeply-held frustration among minorities.

That’s why, despite what looks like intractable problems to white Democrats, minority voters are more optimistic about the future than their white counterparts. That Obama was able to become president and get stuff done is an enormous source of not only pride, but hope. The Kaiser Family Foundation found that more than half of young black and Latinos believe their lives will be better than their parents, compared with less than a third of young white people. On many measures, black people have seen much worse days—the black unemployment rate neared 17 percent at the height of the Great Recession and is less than half that now—even as they continue fighting decades-long struggles. Things aren’t perfect, but the progress that has occurred during the Obama era isn’t something they want ignored or downplayed. Given that reality, why would they believe in the need for a revolution?

That’s why Clinton’s full embrace of Obama during the campaign and her promise to improve, not dismantle, his policies was political brilliance in a Democratic primary in which a candidate can’t expect to win without a large share of the minority vote. The only way so many talented writers and political observers could miss the racial divide within the Democratic Party this election cycle is to either ignore the overwhelming data, or to forget (or pretend) that young, minority Democratic voters don’t exist.

Nate Silver at FiveThirtyEight.com has shown that Clinton’s victories look much more like the Democratic Party—which, with a projected 54 percent white vote this year, will be majority-minority long before the country is—than do Sanders’ wins. Even in Sanders’ upset in Michigan, pundits were claiming he had made a breakthrough with black voters because he lost them only by 35 percent points. And exit polling data in Nevada that showed him edging Clinton among Hispanics is widely suspected to be wrong, given where Clinton racked up votes in that state.

Think about this. According to Reuters/Ipsos polling in February, the Vermont senator received his strongest support among black voters from those aged 18-29—but only a third of that group backed him. That’s right. For all the talk about Sanders’ unqualified young voter support, Clinton had a double-digit lead among the youngest black voters nationwide.

Data from the Pew Research Center underscores the importance of not confusing white young voters for all young voters. It found that nearly 60 percent of Hispanics are either millennials or younger. The same can be said of half of black Americans and 46 percent of Asian-Americans, compared with only 39 percent of white Americans. Each of those groups may be turned off by Trump and have more sympathetic views of #BlackLivesMatter than their parents, but that should not be mistaken for lock-step agreement on some of the most vexing issues we face. Research shows that white millennials’ views on important racial measures—believing that blacks are lazier and worse off financially because of lack of motivation—is eerily similar to their parents and grandparents, though they are less likely to proclaim it publicly. That will have a direct impact on policy decisions going forward.

The racial blind spots evident among otherwise perceptive pundits and Democratic officials reminds me of the “Friends” era. That comedy dominated TV, fueled mostly by white viewers, while one of the top shows among black viewers at the same time was “Girlfriends” on BET. White viewers could list the quirks of Elaine and George on “Seinfeld” in rapid fire succession as black viewers wondered about the latest shenanigans of Cole and Bruh Man on “Martin.” Neither group knew much about popular telenovelas on Univision or noticed the lack of Asian-American leads on the highest-rated network shows.

The Kaiser Family Foundation found that roughly 68 percent of young white people socialize with mostly or only white people while about two-thirds of young blacks and Latinos report they have a more diverse set of friends and acquaintances. But a fragmented viewership framed by racial divides is less concerning than is a fragmented vision within a major political party.

Obama saved the party from having to cope with that reality in 2008 because his liberalism was more liberal than Clinton’s, at least it was perceived to be. That attracted young white voters, as Sanders is doing this year. But he also had minority voters excited.

Clinton, for all of her supposed faults, has run a campaign so tactically effective she has been able to pull together a coalition similar to Obama’s. This may be even more impressive than what Obama accomplished given that she is the ultimate insider in an anti-establishment year. The things that have convinced white progressives, and a handful of high-profile black intellectuals and personalities, that she isn’t worthy of the nomination have not turned off minority voters, young or old.

She’s been so effective this year probably because she couldn’t ignore the racial divide during her bruising primary battle with Obama. In some ways, she exploited that divide. As she fell behind in 2008, she began talking about “hard-working white Americans” while her husband downplayed Obama’s important victory in South Carolina, where more than half of the Democratic primary voters are black. History has repeated itself, with Sanders and his surrogates seemingly dismissing the results in the South—a region that is home to a majority (54 percent) of black Americans. (The Northeast, by comparison, is home to 18 percent of black Americans.)

After Sanders tried but couldn’t connect with enough minority voters—despite the best efforts of Cornel West, Michelle Alexander, Spike Lee and Rosario Dawson, among others—his campaign began focusing mostly on white voters to win the nomination the way Clinton tried to do eight years ago. While the GOP’s effort to turn out more white voters because it has failed to make the party more palatable to minority voters gets the most attention, the two strongest challengers within the Democratic Party during the past two contested primary cycles essentially tried to do the same. That should be more troubling for a party that is supposedly embracing diversity than a party that lost its hold on the minority vote half a century ago.

The evidence of the racial divide lies even within the general election matchup polls Sanders and his supporters love to cite. He leads in a potential matchup with Trump by a larger margin than does Clinton. But that’s largely because Clinton’s minority voters would eagerly back Sanders as the Democratic nominee. Latinos hold a similar rate of favorability for Clinton and Sanders and would vote for either Democrat against Trump in nearly the same percentage, according to a poll by Latino Decisions.

Minority voters have been watching in horror as millions of Republican voters choose Trump either because of, or despite, his open bigotry. The Sanders supporters who toy with the idea of shunning Clinton in November and allowing Trump to become president to force a revolution that Sanders couldn’t deliver are playing with fire. To minority voters, Trump’s candidacy feels like an existential threat. It’s one thing for Republicans to either ignore or embrace his racism; the party already seems unwilling or incapable of making the kinds of adjustments it must to attract more non-white voters. It’s quite another for white Democrats to not appreciate how liberal minorities feel about the possibility of a Trump presidency and what that would say about the state of racial progress in America. It would be a slap in the face, the latest sign that a kind of white privilege—throwing a temper tantrum because they don’t get their way despite how much it hurts people of color—is deeply rooted within liberal, Democratic ranks as well.

Even if Sanders supporters come around to vigorously try to defeat Trump, as most expect to happen come November, the racial reckoning would only have been delayed. The GOP has whiffed on the emerging racial dynamics of the country because it seems stuck in a defensive crouch, borne of having to weather (oftentimes) unfair and exaggerated claims of racism. But the GOP remains willfully blind to the racial angst that animates too many in its party, or the disparate racial impact of some of the party’s signature policies, such as voter ID laws, and the hostility its base has for comprehensive immigration reform.

But Republican vulnerabilities are not automatically Democratic strengths. Democrats may end up whiffing on this issue, too, because the party may succumb to the myth that an increase in diversity is a balm for deep, racial wounds that date back to before this country’s founding. Diversity, they should realize, brings its own set of problems and tensions.

Many Sanders supporters believed his push to regulate Wall Street and solve economic inequality would resonate with minority voters. It didn’t because minority voters know that liberal policies alone won’t reverse decades of racial inequalities. They have been loyal members of liberal unions where white Democrats received plush jobs, even if they were no more qualified than their black colleagues. They’ve seen the same thing in liberal Hollywood and the supposedly liberal world of the media, whose top ranks remain mostly white.

Even though the senator from Vermont began speaking about criminal justice and other types of racial reform, minority voters weren’t convinced he would make those policies a priority. Democrats can waste time debating why minority voters should have connected better with Sanders—and get caught in a condescending discussion about why white Sanders supporters know what’s better for minority voters than minorities do themselves—or they can begin the more difficult work of coming up with strategies to deal with a divide that will show itself in a more pronounced and public way once Trump exits stage left.