Driven by its high poverty rate, Mississippi ranks low on health and wellness. It has one the highest rates of obesity, heart disease, and diabetes in the country, as well as the highest mortality rate for infants and adults. These ills are worst among its black residents: 43.2 percent of Mississippi blacks are afflicted by obesity and its associated problems and 44 percent live at or below the poverty line, compared with a—still high—30.2 percent obesity rate and 16 percent poverty rate for whites.

Which is to say that, more than anywhere else, the Affordable Care Act is necessary in Mississippi. But, as Sarah Varney describes in a vital piece for Politico Magazine, the state’s Tea Party–tinged Republican leadership—including Gov. Phil Bryant—refuses to budge. Not only did it shutter a state-run private exchange for individuals to purchase health insurance, it refused the Medicaid expansion, which would have extended coverage to those living in desperate poverty. The latter consequence is especially destructive.

As designed, the Affordable Care Act provides Medicaid for everyone at or below 133 percent of the poverty line and subsidized private insurance for everyone above. Chief Justice John Roberts and the Supreme Court made the expansion optional, but they failed to extend the subsidies to poorer families, which left a gap. If you’re too poor to qualify for subsidies—but don’t qualify for the present Medicaid program in your state—you’re left in the cold. In Mississippi, this leaves 138,000 residents—most of them black—with no insurance options at all.

In addition, the state’s full rejection of the ACA has thrown the existing hospital system into chaos. “[The hospitals] had been banking on newly insured patients to replace the federal support for hospitals serving the uninsured, which was set to taper off as people gained coverage,” writes Varney. “Now, instead of more people getting more care in Mississippi, in many cases, they would get less.” It’s a disaster. A worsening of conditions for a state that—Varney notes—is already last in life expectancy, per capita income, and child literacy.

We know why Mississippi Republicans refuse to work with the ACA: A hyper-ideological, small government conservatism that disdains social programs and public investment. But it’s worth a look at the history behind that conservatism, which lives strongest in Mississippi but exists throughout the Deep South.

Mississippi has poor social outcomes and a threadbare safety net. It also has—and has long had—the largest black population in the country. And it’s where slavery was very lucrative, and Jim Crow most vicious. This is not a coincidence.

In Mississippi—as in the rest of the South—white supremacy brought a politics of racist antagonism. For instance, the Civil War was hardly over before, notes historian Eric Foner in his book Reconstruction, it passed the first of the “Black Codes” that would limit freedom for freedpeople:

Mississippi required all blacks to possess, each January, written evidence of employment for the coming year. Laborers leaving their jobs before the contract expired would forfeit wages already earned, and, as under slavery, be subject to arrest by any white citizen. A person offering work to a laborer already under contract risked imprisonment or a fine of $500. To limit the freedmen’s economic opportunities, they were forbidden to rent land in urban areas. Vagrancy—a crime whose definition included the idle, disorderly, and those who “misspend what they earn”—could be punished by fines or involuntary plantation labor; other criminal offenses included “insulting” gestures or language, “malicious mischief,” and preaching the Gospel without a license.

Other states would follow suit, but Mississippi’s codes would stand as the most severe, setting a pattern for the next century. The rest of the South might have the same kind of racist customs, but they were worst in the swamps and cities of Mississippi. In fact, the state had fewer Jim Crow laws than its neighbors; they just weren’t needed. Instead, there was a status quo of violence and ruthless suppression. Mississippi had the highest number of lynchings—539 between Reconstruction and the civil rights era—and the most severe convict leasing, where it became a kind of neoslavery.

Where they existed, public services were sparse and utterly segregated. Anything public had to be kept separate from blacks, or degraded, if that wasn’t possible. To get a sense of the scale of white resistance in Mississippi, consider this: During the civil rights movement, white supremacists built a network of state and private agencies to wreak havoc on black activists with surveillance, economic reprisals, and extreme violence. One of them was the Mississippi Citizens Council, and it, writes historian Joseph Crespino, “[P]oliced a white racial authoritarianism that ran roughshod over the civil and political rights of white and black Mississippians both. Because of the Council’s influence, no place in the United States … came closer to resembling the repressiveness of apartheid South Africa than did Mississippi.”

More than a half-century later, and all of this is dead. But the ideas and culture it built are not. And why would they be? For nearly 100 years, Mississippi was a white supremacist police state. Of course this made a mark on its culture. Of course these ideas of exclusion—and specifically, of racial hostility to outside interference and public goods—are still embedded in the structure of its politics.

Today, Mississippi is politically polarized along racial lines. Whites are Republicans, blacks are Democrats, and the former controls state politics. Public investment isn’t just disdained, it’s attacked as racially suspect. “The Republican Party has never been the food stamp party, or the party of pork until desperation set in with Thad Cochran’s re-election bid,” said state Sen. Angela Hill during the Mississippi Senate Republican primary, in reference to Sen. Cochran’s outreach to black voters. The state is harshly carceral—jailing more people per capita than almost anywhere in the country, the majority of them black—and has a huge number of all-white private schools while the public school system is largely segregated.

You can understand all of this in terms of ordinary conservatism—and many people do—but this is a particularly strong conservatism shaped by a particularly brutal racial history. It’s a small-government philosophy that has its roots in the pro-slavery thought of John C. Calhoun, emerged as resistance to Reconstruction, resurfaced in the fight against civil rights, and is now mostly ideological, if attenuated—but not separate—from its roots.

What we see in Mississippi—and, in varying degrees, the country writ large—is what was wrought by white supremacy. A society where the racial caste system is still intact but justified by other means. And it’s a caste system that—as we see with the revanchist attacks on health reform—is destroying Mississippi by making it difficult to craft any solutions to the state’s deadly problems.