They always deny it when directly confronted, but make no mistake: Conservatives are coming for your birth control. That much was confirmed yet again on Tuesday when Justice Clarence Thomas issued an unhinged opinion on what was supposed to be an abortion case in which, not to put to fine a point on it, he suggested that the founder of Planned Parenthood, Margaret Sanger, advocated for birth control because she was hoping to kill black people.

At stake was a law that, on its surface, had nothing to do with contraception. It was classic troll-the-liberals legislation from Indiana, signed by then-Gov. Mike Pence, which barred abortion on the basis of race, sex or disability of the fetus. Anti-choicers have long pushed for these laws on the grounds that black women have higher abortion rates than white women, implying, by a leap of logic that’s extreme even for religious fanatics, that black women are the “real” racists and that they get abortions because they hate black children.

Thomas, in his opinion, concurred with this defamation of black women, pointing out that black women have more abortions than white women on average and arguing that “insofar as abortion is viewed as a method of ‘family planning,’ black people do indeed ‘tak[e] the brunt of the ‘planning.’'”

This “black women are the real racists” argument has been popular in anti-choice circles for a long time — there are frequent accusations that black women are literally committing “genocide” against black people — mostly because it lets a bunch of white Republicans feel that they’re somehow the good guys for trying to take away women’s health care services. It’s also a way to stigmatize Planned Parenthood by insinuating the founder was a white supremacist. But, of course, this argument is itself both deeply racist and deeply misogynist, in that the implication is that black women hate their children and want to kill them.

In reality, the reason black women get more abortions than white women is simple: They have more unwanted pregnancies. That’s because black women, thanks to structural racism, have significantly poorer access to contraception. Due in no small part to the Affordable Care Act and its provision requiring insurance companies to cover contraception, abortion rates have been falling for all groups of women in recent years — and especially for black women.

But conservatives are swiftly, if still stealthily, moving to reverse those trends, and are fighting to make contraception harder to get, so that the unintended pregnancy rate will starts soaring again. Thomas did his part in that opinion by aggressively promoting the long-standing anti-choice conspiracy theory that Sanger advocated for birth control because she supposedly had it out for black people.

We know that Thomas’ rant was an attack on birth control because, as he admits, Sanger was not actually supportive of abortion, which she called an “abnormal, often dangerous, surgical operation” that she strongly condemned as “dangerous and vicious.”

Sanger’s hatred of abortion was wrong-headed, but in fairness, it was likely rooted in her experience as a nurse working in the tenements in the Lower East Side of Manhattan in the early 20th century. There she bore witness to the gory injuries caused by “slippery-elm sticks, or knitting needles, or shoe hooks into the uterus” to which women resorted in order to abort.

Thomas tries to massage his opinion into making some approximate sense by saying that the arguments against contraception “apply with even greater force to abortion.” This is a legalistic version of the “contraceptive mentality” argument popular in anti-choice circles, which holds that contraception causes abortion by convincing people that non-procreative sex is acceptable. If people only had sex for procreation and within the bounds of heterosexual marriage, the argument goes, then there would be no need for abortion.

(Of course, the idea that there was a time when people limited their sexual activity to procreative purposes is laughable. Also, the use of abortion predates the birth control movement in North America by hundreds, if not thousands, of years.)

There is no doubt, as Thomas makes abundantly clear in this opinion, that Sanger was an advocate of the noxious early-20th-century pseudoscience of eugenics, which suggested that the human race could be “bettered” by manipulating breeding to improve human “stock.” But it’s historically inaccurate to imply, as Thomas and the anti-choice activists he’s cribbing from do, that Sanger started the birth control movement because of her belief in eugenics. The historical record is clear on this: Sanger began advocating for birth control to empower women and then latched onto the eugenics movement as a way to increase interest in the issue.

Sanger advocate for some highly distasteful eugenics ideas at times. But it’s flat-out false to imply, as Thomas does, that she supported forced sterilization or that she was trying to get rid of black people. In her writings, she insisted that birth control must be “autonomous, self-directive, and not imposed from without” and that no one should “be endowed with the authority to order anyone to be sterilized.”

More importantly, Thomas is being disingenuous in his suggestion that Sanger was targeting black people for eugenics purposes when she teamed up with activists like W.E.B. Du Bois to open clinics geared towards helping black women obtain contraception. As Imani Gandy wrote at Rewire in 2015, this project was literally the opposite of a racist attack on black people. It was an explicit effort to make services available to black people that only whites previously had access to. Sanger believed that birth control helped people exert more control over their lives and help themselves economically, and this project was explicitly meant to help people in the black community empower themselves.

“Due to segregation policies in the South, the birth control clinics that opened in the 1930s were for white women only. Sanger wanted to change that,” Gandy explained.

As Gandy notes, Sanger explicitly rejected the idea of racial eugenics, saying she had encountered a man who tried to give her money if she would “cut down” on the number of black people.

“That is, of course, not our idea. I turned him down,” Sanger said. “But that is an example of how vicious some people can be about this thing.” She added that her purpose was to reduce “sufferings for all groups.”

Despite his protestations to the contrary, Thomas’s opinion is clearly meant to bolster the growing efforts of the religious right to expand the war on reproductive rights past attacks on abortion, onward to reducing access to contraception.

Demonizing Margaret Sanger is clearly meant to stigmatize her legacy. But her legacy is not abortion — which, again, she opposed — but birth control. It was Sanger who coined the term “birth control.” It was Sanger who went to jail repeatedly for teaching women how to prevent pregnancy. And it was Sanger who envisioned the concept of the birth control pill, eventually securing the funding that allowed it to be developed. So when anti-choicers seek to turn her into a villain, their goal is to taint contraception by association and create a moral case for restricting access.

There’s no small amount of hypocrisy in play here. Clarence Thomas sits on a court that was literally created by slave-holders, including George Washington, who signed the act that created the Supreme Court. And Thomas adheres to an “originalist” judicial philosophy which claims that the beliefs of the nation’s founders — who were, whatever their better qualities, a bunch of racists who literally wrote legal slavery into the founding documents — should matter more in jurisprudence than current, more progressive social mores. Thomas presumably doesn’t believe that the U.S. Constitution or the Supreme Court is permanently tainted by these racist associations. But when it comes to restricting women’s rights, he is happy to advance a much shakier case of guilt by association.

The good news is that there’s not much that’s legally binding in this rant from Thomas. His opinion was tied to a court decision that actually throws out Indiana’s law banning abortions done on the basis of race, sex or disability. (To be clear, there is no evidence that the first two kinds of abortions even happen. Those seem to be figments of anti-choice activists’ collective racist imagination.) For now, the claim that reproductive rights must be restricted on the basis of some imaginary eugenics threat against people of color has no legal importance.

The bad news, however, is that by elevating right-wing conspiracy theories about Margaret Sanger, Thomas has given the blessing of a Supreme Court justice to the escalating war on birth control. The pretense that the right’s campaign against reproductive rights is about “life” is fast fading away. Instead, Thomas bluntly suggests that women can’t be trusted to make their own decisions about when to give birth because they will use that power for unsavory or even racist purposes. That kind of argument isn’t just about abortion. It’s about the idea that society must control or restrict any method women employ to control childbirth.