It was a cold March night when Dr. Martin Luther King, Jr. turned his pulpit towards health care. Speaking to a packed, mixed-race crowd of physicians and health-care workers in Chicago, King gave one of his most influential late-career speeches, blasting the American Medical Association and other organizations for a “conspiracy of inaction” in the maintenance of a medical apartheid that persisted even then in 1966.

There, King spoke words that have since become a maxim: “Of all the inequalities that exist, the injustice in health care is the most shocking and inhuman.” In the moment, it reflected the work that King and that organization, the Medical Committee for Human Rights (MCHR), were doing to advance one of the since-forgotten pillars of the civil-rights movement: the idea that health care is a right. To those heroes of the civil-rights movement, it was clear that the demons of inequality that have always haunted America could not be vanquished without the establishment and protection of that right.

Fifty-one years later, those demons have not yet been defeated. King’s quotation has become a rallying cry among defenders of the Affordable Care Act, the landmark 2010 legislation that has come the closest America has ever been to establishing a universal guarantee of health care. Their position is in peril, as the Republican effort to repeal the law and create a replacement that leaves 22 million more people uninsured over the next decade and will slash Medicaid enrollment by 15 million now sits just days away from possible passage.

People of color were the most likely groups to gain coverage and access to care under the ACA, and in the centuries-old struggle over health, they have never been closer both to racial equality of, access and to, the federal protection of health care as a civil right. But if Republicans have their way, that dream will be deferred.

Just as the ACA’s defenders find themselves between a once-in-a-generation victory and a potential equally devastating loss, so the MCHR found themselves in 1966. King delivered his address just months after breakthroughs a century in the making. In the height of the movement in the early 60s that brought sweeping changes in voting rights, integration, and education, civil-rights actors had also won major victories in a push for universal health care. Chief among those victories were two of the defining pieces of 20th-century American policy: the Civil Rights Act in 1964 and the passage of Medicare and Medicaid in 1965.

Of course, the Civil Rights Act might not seem like much of a health-care bill, and Medicare isn’t usually counted among major civil-rights victories, but as detailed in in health-policy researcher David Barton Smith’s The Power to Heal: Civil Rights, Medicare and the Struggle to Transform America’s Health System, they were complementary pieces of a grand civil-rights strategy.

Key to that strategy was the 1963 Simkins v. Cone lawsuit, filed by dentist and Greensboro, North Carolina, NAACP leader George Simkins against segregation in the local hospital. In finding in Simkins’s favor, the The Fourth Circuit Court of Appeals ruled for the first time that institutions receiving federal funds could not abide by the “separate but equal” legal underpinning of Jim Crow. That ruling in turn helped shape Title VI of the 1964 Civil Rights Act, which bars segregation and discrimination among entities that receive federal funding, and to this day provides the most effective legal mechanism for federal civil-rights cases.

The NAACP and the National Medical Association—the black professional organization that was formed because the the AMA was segregated—led by W. Montague Cobb fought for the passage of the first major American health reform policy in Medicare and Medicaid. They organized direct action, legal challenges, and lobbying efforts in support of the reform, in direct opposition to most of the rest of the segregated medical establishment.  “Medicare was in a very real sense a creation of the civil-rights movement,” Smith says. In the ensuing hearings, Cobb was the only leader of any medical association to testify in favor of Medicare and Medicaid.

In 1965, just a week before also passing the Voting Rights Act, Congress passed the amendment to the Social Security Act that authorized Medicare and Medicaid, with Cobb as the witness to Lyndon B. Johnson’s signing ceremony. The law’s effects on segregation were felt immediately. Since Medicare’s universal coverage of elderly people brought federal funds to about every hospital in America, it also bound them by Title VI’s nondiscrimination clauses, which essentially ended segregation in those hospitals—some of the last public arenas in which Jim Crow legally held sway. Medicare was the final federal legal blow for de jure segregation, and without it, there would still be few legal mechanisms to force hospitals to integrate. It’s hard to overstate how much Medicare and Medicaid themselves did to end formal segregation.

By the same token, it’s hard to overstate just how deeply that waning segregation had mattered in health outcomes. From the end of slavery onward, American health-care has been deeply bifurcated along the lines of race, and that bifurcation was always reflected in how well people lived and how early and often they died.

Jim Downs’s Sick From Freedom: African-American Illness and Suffering During the Civil War and Reconstruction explores how that bifurcation began, chronicling the role of the Reconstruction-era Freedmen’s Bureau in fighting severe epidemics among formerly enslaved populations. Although it is known mostly for its ill-fated and ill-administered attempt to guide freedmen through emancipation, in its brief life from 1865 to 1872, the bureau also became the first public-health agency for black people, as existing municipal and charity health infrastructure built for white people in the South denied them aid. “These institutions, which had historically offered universal support to the poor and dispossessed,” Downs writes, “began to claim that they would only assist ‘citizens.’”

After white supremacy brought Reconstruction to a violent and premature end, medicine evolved along those same dividing lines of white citizens and black outcasts. America’s developing peculiar, private, decentralized, job-pension-based health-care infrastructure was the only fit for a modernizing society that could not abide black citizens sharing in societal benefits, and one where black workers had often been carved out of the gains of labor entirely.

As German Prime Minister Otto Von Bismarck’s Health Insurance Bill of 1883 created the first modern national health-care system, and as many other countries moved down the path to truly nationalized, universal health care, America instead largely expanded the existing segregated system of local private providers and religious-based charity care. In essence, the United States’s peculiar private-based health-care system exists at least in part because of the country’s commitment to maintaining racial hierarchies. The results were deep racial disparities in almost every major disease, an enduring gap in lifespans and mortality, and the creation of entirely separate medical and public-health infrastructures.

According to Smith, key figures within the resulting isolated black health infrastructure  “ended up becoming the real leadership of the local chapters of the NAACP,” and spearheading local movements against Jim Crow. Emerging leaders in the mid-20th-century included people like Simkins and Cobb, as well as national NMA president and Mississippian T.R.M. Howard, who mentored the Evers brothers and Fannie Lou Hamer, and played a leading role both in the investigation of Emmett Till’s death and also in the creation of Medicare.

The Medical Committee for Human Rights inherited that mantle of health-care and civil-rights activism and organizing in the 60s. Thomas J. Ward’s Out in the Rural: A Mississippi Health Center and Its War on Poverty details how the MCHR coalesced from a group of black and white physicians participating in Freedom Summer in 1964. Among that group, public-health champions H. Jack Geiger, Bob Smith, and John Hatch pushed to build the first rural community health center in the United States, in Mound Bayou, Mississippi, and created community health centers as one of Lyndon B. Johnson’s “War on Poverty” programs. They also set their sights squarely on universal health-care as a necessary component of the civil-rights agenda.

The passage of Medicare and Medicaid in 1965 helped deliver some portion of that agenda, but as with every other civil-rights victory, the backlash was strong. The MCHR, NAACP, and NMA would encounter resistance to both the prospect of universal health care and to the use of existing systems to end health disparities that utilized the full muscle of white supremacy.

Even as members of the MCHR listened to King’s speech in Chicago, the AMA was digging their heels in against the prospect of integrating the expanding Medicare and Medicaid programs. Using the successful, red-baiting cudgel of “socialized medicine,” and armed with the first major political advertising firm, the AMA, health-care industry organizations, and their conservative allies had already defeated a 1947 proposal from President Truman to create a true national health-care plan. Although they could not stop the remnants of that plan from eventually becoming Medicare and Medicaid, that coalition was able to obstruct further progress towards coverage for “able-bodied” adults and the creation of a coherent universal guarantee to care. They might not have known it at the time, but for those activists in 1966, health care had already become a dead end.

After King’s death in 1968, and the disintegration of the civil-rights movement, opposition from the AMA-led coalition would stymy the last organized effort from the MCHR to create and pass a single-payer bill. That failure also cemented the basic composition of American health-care: a patchwork dominated by private employer-based insurance, where non-elderly people who couldn’t afford or didn’t have such offers, and didn’t fall into narrow special Medicaid eligibility groups were largely left out. And it’s no coincidence or secret that those left out were more likely than not to be people of color.

That basic shape remained all the way until 2010, when Democrats and President Obama pulled off the multi-pronged policy and legislative maneuver that became the ACA.

Obamacare, as that law came to be known, wasn’t the universal health-care guarantee or the single-payer system that civil-rights activists had pushed for decades, especially after the Supreme Court gutted the core provision of its Medicaid expansion to low-income adults and made it state-optional. Instead, Obamacare sidestepped the political pitfalls of such a plan by attempting alchemy, hoping to entice states to choose to expand Medicaid guaranteed coverage for low-income people, creating a subsidy and non-participation penalties instead of a guarantee for middle-income people, and generally trying to bend the health-care industry against its own exclusionary nature with large sums of money.

Still, even though the ACA isn’t a single-payer or universal system, it did a better job than the status quo ante at ensuring some sort of access to care. According to J. Nadine Gracia, the former Deputy Assistant Secretary for Minority Health and the Director of the Office of Minority Health at HHS—positions and an office that were themselves reauthorized and expanded by Obamacare—the ACA’s benefits were immediately realized in communities of color. “The Affordable Care Act is the most important law to help reduce health disparities since the passage Medicare and Medicaid,” Gracia said, “because the law is addressing issues of access, affordability, and quality of care, which have all been obstacles and barriers that relate to the health of minorities.”

For former Surgeon General David Satcher, whose work has helped popularize the concept of health disparities and kept the dream of universal coverage alive in the interim between Medicare and Obamacare, the ACA is a stepping stone. “I think we've made some progress with the Affordable Care Act, but as you know that has been greatly limited by the politics of Washington,” he told me. “We haven't gotten half as far as we could've gotten with that because the ultimate goal is that everybody will have access to quality health-care.” But if current events are any indicator, half as far may be as far as America gets.  

There is a broad consensus among health organizations (now including the AMA), former officials like Satcher, and the former titans of the civil-rights movement that the Better Care Reconciliation Act (BCRA) in the Senate and the American Health Care Act (AHCA), its sister bill in the House, will move America away from eliminating racial inequalities in health and health care. In addition to changes in private insurance that will make plans less comprehensive and less useful for sicker and poorer people—within which people of color are overrepresented—the BCRA also eliminates the ACA’s Medicaid expansion to low-income adults and constrains the underlying Medicaid program to the point where in the future states will have no choice but to cover fewer people.

In essence, the BCRA not only erases the ACA’s market-oriented experiment in health equity, but also strikes a blow at the previously established elements of “socialized medicine” that were longtime objectives of the civil-rights movement. In this—as is true of other civil-rights victories that were the bedrock of the 50s and 60s liberation movement, like education and voting rights—a central tenet of American freedom now finds itself in danger of simply vanishing. The country cannot follow through on its commitment to equal protection for life and liberty under the law without addressing fundamental inequalities in mortality.

It’s worth noting that much of the animus behind the opposition to Obamacare is tied to race. Studies have shown that racial prejudice is a good predictor of opposition to the bill, and its central policy of Medicaid has always been subject to implicit racial biases in public opinion. A recent Kaiser Family Foundation study found that Republican voters tend to view Medicaid as welfare, with all the attendant stereotypes and dog whistles.

Much of that implicit opposition was summed up in a famous 2009 rant from conservative radio host Rush Limbaugh, who called the plan “reparations,” and said it reflected Obama’s belief that “this country was immorally and illegitimately founded by a very small minority of white Europeans … and it’s about time that the scales were made even.” The irony is that Mr. Limbaugh was correct about the bill in one respect: It did disproportionately help the poor and people of color, and in doing so, begin to correct a centuries-old injustice.

In a statement defending his signature policy in May, President Obama articulated just why the ACA was such a historic piece of legislation. “When I took office, millions of Americans were locked out of our health care system,” he wrote. “We finally declared that in America, health care is not a privilege for a few, but a right for everybody.”

Contrary to Obama’s statement, the ACA actually didn’t manage to make health care a right, nor has it allowed all of those locked-out people into the system. But it does come closer to those goals, and does grant access to millions of people of color who had been left out for generations. Unfortunately, the law has also triggered the same conservative immune response that killed single-payer in the past; the same kind of response that King so eloquently railed against in Chicago.

With 51 votes and a presidential signature, Republicans can begin turning back the clock.