His view stands in stark contrast to that of many reproductive rights and medical groups , who argue that policing a woman’s reason for having the procedure not only infringes on her constitutional rights, but also paves the way for even more restrictive legislation around women’s bodies.

“Technological advances have only heightened the eugenic potential for abortion, as abortion can now be used to eliminate children with unwanted characteristics, such as a particular sex or disability,” Thomas wrote, mentioning eugenics more than 100 times throughout his opinion.

In his 20-page concurring opinion , Thomas argued that “abortion is an act rife with the potential for eugenic manipulation,” which is the practice of trying to improve the human population by eliminating “inferior” genetic traits.

Supreme Court Justice Clarence Thomas agreed with a majority of his colleagues on Tuesday that they should wait for more legal analysis before they rule on the idea of banning abortions based on a fetus’s race, disability or gender . The high court’s reigning conservative voice still used the opportunity to stoke fears that abortion is already a tool used worldwide to eradicate undesirable people.

To give the justice his due, support for eugenics has historically been at the heart of horrors like the Holocaust and forced sterilization laws. Thomas, however, insisted that the fight against eugenics via abortion is a pressing problem today.

″[A] growing body of evidence suggests that eugenic goals are already being realized through abortion,” he wrote before launching into a history of comments made by abortion advocates over the last 100 years ago to make his case.

But there’s a glaring problem with his thinking: We now have decades of evidence in the U.S. to show that women are perfectly capable of using birth control and abortion to plan their lives without becoming agents of a genetic cleansing conspiracy. Moreover, the evidence Thomas cites lacks important context.

What he gets wrong about race and abortions

In one of his more head-scratching claims, Thomas painted a picture of the modern abortion rights movement as a threat to black America.

“The reported nationwide abortion ratio — the number of abortions per 1,000 live births — among black women is nearly 3.5 times the ratio for white women,” he wrote. And he pointed to concerns raised by the NAACP and other black groups in the 1960s that Planned Parenthood had taken a “‘ghetto approach’ to distributing its services.”

It’s true that black women in the U.S. have a higher rate of abortion than some other demographics. But that’s because widespread inequality in health care access leaves many black women with less exposure to sex education, birth control and other tools to prevent unwanted pregnancies in the first place. Planned Parenthood has said it’s well aware of the problem and that its members work on outreach in minority communities.

Thomas’ suggestion also ignored the disturbing rates of maternal mortality among black women ― yet another consequence of health care inequalities. In a floor debate over Missouri’s strict new abortion ban earlier this month, state Rep. Cora Faith Walker (D) spoke out against the disproportionate risks that black women like her faced.