Bernie Sanders’s confrontation with members of Black Lives Matter should teach a lesson to everyone engaged in the struggle to defend Social Security: Unless the campaign for economic equality recognizes the need to prioritize racial equality as well—that racial and economic issues are not separate—preserving and expanding Social Security will become increasingly difficult.

In politics, context is everything. The most passionate advocacy, even for an utterly righteous cause, can sound presumptuous when the advocate ignores another issue more important to the same audience. Witness Sen. John McCain’s recent humiliating treatment by the Navajo, who chased him off their reservation on August 16, when he came to discuss a feel-good memorial to the World War II Code Talkers—but refused to address complaints that he had failed to protect tribal water rights or to oppose a copper mine that’s about to be built on Oak Flat campgrounds, an area of spiritual significance to the Apache.

On the opposite end of the political spectrum, Sen. Bernie Sanders recently received a similar lesson. On July 18, Black Lives Matter protesters disrupted a Netroots Nation forum in Phoenix featuring Sanders and former Maryland Gov. Martin O’Malley; on August 8, Black Lives Matter struck again as two members took over the podium just as Sanders was about to start speaking.

On both occasions, and within seconds, the coalition progressives Democrats need to hold together to win elections seemed to fall apart, in a very ugly way. According to the Seattle Times, “some in the mostly white audience booed and hissed as they urged protesters to let the senator talk. A few yelled for police to make arrests.” Marissa Johnson, one of the protesters, “shot back at the crowd, ‘I was going to tell Bernie how racist this city is filled with progressives, but you did it for me,’ accusing the audience of ‘white supremacist liberalism.’”

Sanders himself seemed not to believe what he was hearing.

“I am disappointed that two people disrupted a rally attended by thousands at which I was invited to speak about fighting to protect Social Security and Medicare,” he said. “I was especially disappointed because on criminal justice reform and the need to fight racism there is no other candidate for president who will fight harder than me.”

The coming weeks will show whether the Sanders campaign fully comprehends how arrogant and paternalistic that sounded. It’s true that Social Security is disproportionately vital to disabled and retired African American workers and their survivors, but in our market-based economy, the first priority is always jobs—and the opportunity to qualify or be considered for a good job, not to mention one’s prospects once that job is obtained, are still deeply impacted by racial prejudice. Likewise, while Social Security provides a dependable minimal stream of income in retirement for lower-income working people, what kind of life does that provide when one is effectively red-lined out of middle-class neighborhoods, subjected to constant police intimidation and violence, and victimized by the “poor tax” through lack of access to reasonably priced banking and other services?

It’s not just that Social Security isn’t politicians’ magic path to the hearts of American working households. The problem goes back to the fact that in American politics, economic and racial issues are treated as separate and, generally, unequal, when in fact they are closely bound up.

On the 80th anniversary of the passage of the Social Security Act, it’s important to remember this lesson. That law, along with much of the legislation that launched the modern welfare state, was formulated at a time when black people were effectively barred from voting in the region they occupied in the greatest numbers. Politically, much of the New Deal was geared to appeal to urban white working families—the core of the Democratic Party outside the South. So it was easy to address economic and racial issues discretely, or to argue that if the one is taken care of, the other will surely follow. Improvements to Social Security over the next 35 years enabled blacks to enjoy its benefits, but liberal Democratic politicians continued to fool themselves that economic issues were, somehow, color-blind.

It’s been a long time since this made any political sense. The beginnings of the contemporary conservative counterattack against the New Deal—including Social Security—date from the early 1970s, when the law-and-order backlash against the Civil Rights Movement was in full swing. In those years, the state’s preferred response to the problems of black Americans switched from housing, education, and social services to gentrification, militarized policing, and three-strikes-you’re-out laws. Programs to help the poor were reinterpreted as doing them harm by reducing their motivation to self-improve. Aid to Families with Dependent Children (“welfare”) was the first target, in part because it wasn’t an “earned” benefit and therefore easy to caricature as a giveaway.

At the same time, however, Social Security came under attack. Drastic cuts were being proposed under the Cater administration, and the retirement age for full benefits was raised for the first time—effectively cutting benefits—in 1983; by then, many on the right and center-right were regularly referring to Social Security and Medicare as “entitlements,” a form of middle-class welfare. What was bad policy for the African American poor, it stood to reason, was also bad policy for the white middle. Members of the Reagan administration openly argued that Social Security undermined families’ incentives to support their older members and that it eroded personal savings and encouraged dependency on government—a position Mitt Romney merely reiterated in his notorious “47%” speech in 2012.

As for the police violence that has caught the public’s attention in the wake of Michael Brown’s and Eric Garner’s killings, Bernie Sanders certainly isn’t the only presidential candidate who has yet to grant it the urgency it demands. Real estate mogul Donald Trump declared that if anyone attempted to take over a podium in the same manner that Black Lives Matter appropriated Sanders’s, he’d fight them, and accused Sanders of “weakness.” Hillary Clinton, confronted in her turn by BLM activists, evaded their question whether anything “in her has changed” since the killings, given that she had lobbied for the 1994 Violent Crime Control and Law Enforcement Act that helped propel America’s incarceration levels to the highest in the world. This despite the fact that her husband, former President Bill Clinton, who signed the bill, has publicly regretted doing so.

Republican insensitivity on the issue is no surprise. (Wisconsin Gov. Scott Walker, asked if he’d meet with BLM organizers, said, “I meet with voters. Who knows who that is?”) Clinton’s evasiveness extends to her statements on Social Security, which have distinctly not included support for expanding the program. But Sanders’ response—thus far—to BLM is especially disturbing, since he has set himself up as the standard-bearer for progressives. As such, part of his mission has been to try to win back the support of working-class whites in parts of the country, like the South, where they have turned away from Democrats. Social Security is a big part of what he hopes will be his leverage. But that can’t mean ignoring, or downplaying, an issue that’s a matter of life and death to African Americans.

If progressives want to protect Social Security—as Sanders clearly does—they’ll have to understand that racial and economic issues are not separate. Racial injustice bolsters economic injustice, and the cultural arguments against policies that promote social and economic equity between races can be deployed just as easily against white working people. One of the lessons of the trail of African American lives in the streets of Ferguson, Baltimore, New York, St. Louis, Oakland, and other places is that these victims’ communities can’t wait any longer for the conditions of their lives—which are dictated, to a great extent, by police and prosecutors—to improve. It’s hard to give priority even to Social Security when you live under what’s quickly evolving into a quasi-military occupation.

White progressive politicians need to learn this lesson, and quickly, because otherwise their coalition will fracture and their opponents will be encouraged once again to extend their prescriptions for social “reform” from the urban poor to the white middle class. It’s no answer to lecture African Americans, as Sanders did, that he’s their best hope of having their needs addressed, despite his failure to speak directly to those needs. They’ve heard it too many times before.