Last week, at the Fusion-hosted Black and Brown Forum, moderators asked Vermont Sen. Bernie Sanders if he supported reparations for black Americans. His answer was “No.” “Its likelihood of getting through Congress is nil,” he said. “Second of all, I think it would be very divisive.”

Writing for the Atlantic, Ta-Nehisi Coates critiqued Sanders’ response for betraying a selective radicalism. “Sanders is a lot of things, many of them good. But he is not the candidate of moderation and unification, so much as the candidate of partisanship and radicalism,” writes Coates. “Unfortunately, Sanders’s radicalism has failed in the ancient fight against white supremacy.”

In turn, this sparked a litany of reactions and critiques, all focused on the politics of reparations. The strongest response, from Daniel Denvir at Salon, sidesteps the question of Congress to focus on the claim that reparations “would be very divisive.” For Denvir, this is key: “Sanders might not be a moderate but he is keenly interested in unifying voters,” he writes. Contrary to Coates’ analysis, Sanders is a uniter, with a plan to unify the public around an expansive agenda of economic radicalism. And while reparations might make sense, pursuing them could irreparably damage the Sanders-led “political revolution” that requires support from white Americans who reject reparations.

Put differently, Sanders is a radical politician, and as such, he’s keenly aware of the contours of his coalition. As demonstrated by his rise in the Democratic primary, he might be able to win the nomination—and the primary—on a platform of anti-plutocratic action. Reparations, which force a brutal and substantive reckoning with America’s racist past and present, would shatter that. Which is to say that Sanders’ quip about Congress—which, in its present form, wouldn’t pass single-payer or free college either—is a smokescreen for a shrewd (and correct) political argument.

But how does the political argument fare? Reparations are unpopular because they run into the strongest headwind in American politics: White opposition to programs that target on the basis of race. That includes everything from affirmative action and welfare (pre- and post-reform) to a program like the Affordable Care Act, which some perceived as a racial entitlement that took from the healthy and insured (largely white and middle-class) and distributed to the less healthy and uninsured (disproportionately black and Latino). At least one prominent critic even attacked the plan as a kind of “reparations.” Overall, white attitudes toward blacks are tightly tied to their attitudes toward the welfare state.

The Sanders theory is that you can overcome this with programs that reject targeting in favor of broad and universal benefits. Under single-payer health insurance, everyone has the same access to the health system. Under free college, everyone has access to the same public institutions. If everyone pays in and everyone collects, then there’s no basis for resentment. You can circumvent race, full stop.

But is this true? Let’s go back to white attitudes about government spending. As sociologist Martin Gilens explains in a chapter for the 1998 volume Perception and Prejudice: Race and Politics in the United States, white beliefs about government vary by program. Head Start and job training are popular among whites; welfare and food stamps are not. Even as, in each case, whites see blacks and other minorities as the main beneficiaries by a significant margin.

The difference is that the former challenge a belief that blacks “lack commitment to the work ethic.” Generalized racial resentment plays an important role, but it’s the perception of blacks as “lazy” that acts as the strongest predictor of whites’ welfare views. And the perception is widespread. Forty percent of white Americans say whites are more hardworking than blacks—according to data from the General Social Survey—and 45 percent say “blacks don’t have the motivation or willpower to pull themselves out of poverty.”

Which is why, as Gilens writes in his 2009 book Why Americans Hate Welfare, “Programs that are seen as enhancing the ability of poor people to support themselves … do not evoke the same negative racial imagery.” By contrast, those perceived as undermining the work eithic or unfairly rewarding the unqualified evoke negative attitudes toward blacks, which increases opposition toward the programs themselves. (On the other side, the white public often backs race-targeted programs designed to “help minorities help themselves.”)

The Sanders revolution is multiracial and multicultural, but—like any political victory in present-day America—it depends on white Americans. It’s why he can’t support reparations. They’re too alienating to the white voters he needs to transform the nation’s politics. But this, potentially, is also true of his largest programs, like single-payer. Yes, they’re universal, but as backers argued in response to Coates’ critique, they’re also anti-poverty measures that give major benefits without comparable contributions. In the same way that the Affordable Care Act inspired tremendous, racialized opposition, a single-payer health plan—if seen as a handout and not a “hand up”—might do the same and fracture Sanders’ coalition along racial lines. The revolution might crash on the shores of its realization.

This isn’t a judgment on Sanders, his campaign, or his theory of change. But it’s important to see that the forces that make reparations impossible can also, in diminished but powerful form, curtail his agenda too. Which gets to a larger observation. When Sanders heaps praise on the social democracies of Europe, he neglects the degree to which they rest on racial and cultural homogeneity. Danes are happy to help Danes; Swedes are happy to help Swedes. But that’s true here as well. The New Deal came with racist exclusion, and it took national effort in a global war to build the solidarity needed to expand Social Security and other programs beyond white workers. Unions, as well, struggled with America’s racial hierarchy, where the spoils of national wealth weren’t supposed to go to blacks and other minorities.

The rights revolution of the 1960s ended the implicit contract between white Americans and the national government. Now, benefits were open to everyone. But our politics couldn’t accomodate this change. The New Deal consensus shattered, with most white Americans backing the party that rejects the activist state, and minorities backing the one that does. In a real way, the past 50 years have been a novel experiment in multiracial welfare democracy, and we’re still struggling to see if it’s possible, now against a vocal politics of revanchist ethno-nationalism, embodied by Donald Trump. (With the rise of mass immigration, something similar and more dramatic is also happening in Europe.)

Sanders isn’t just running against Wall Street or the political establishment; he’s running—along with American liberalism—against those forces that reject the multiracial welfare democracy as a project. And the truth is that he can win the presidency and still lose that fight.

Read more of Slate’s coverage of the Democratic primary.