When Marc Lépine murdered 14 women at Montreal’s École Polytechnique in 1989, he claimed that he was “fighting feminism.” When Anders Breivik murdered 77 people in Norway in 2011, he was in large part motivated by his hatred of feminism, which he considered a poison and threat to the future of European men. And when Elliot Rodger killed six people in Isla Vista, California, in 2014, he said he did it to punish young women for rejecting him and sleeping with other men instead.

These massacres were painted as the acts of lone mad men, but they have a clear common thread: a desire to dominate women and a conviction that society oppresses men in favor of women. Those misogynistic beliefs, so depressingly familiar and widespread, have hardened into a more distinct force in recent years, and have been fueled by the election of Donald Trump and the resurrection of white supremacist groups in American political life.

In February, the Southern Poverty Law Center added two male supremacist websites to its list of hate groups, for the first time categorizing male supremacy as an explicit ideology of hate. The ideology of male supremacy, according to the SPLC, represents all women as “genetically inferior, manipulative, and stupid” beings who exist primarily for their reproductive and sexual functions. Gender-essentializing male supremacists rely on cherry-picked science and anthropology to bolster their claims that men are inherently dominant. Not only do women owe men sex, they believe, but men are entitled to take it from them.

“You want to reach a point where you have high expectations of a woman but she has little expectations of you,” wrote Daryush “Roosh” Valizadeh, founder of Return of Kings, in a recent blog post. “She must give you submission while you do as you may.”

Return of Kings is one of the two male supremacist organizations listed by the SPLC. A Voice for Men, founded by Paul Elam, is the other. While Elam’s “men’s rights” movement has enjoyed some favorable media coverage, and he has managed to present himself as a moderate voice for men’s equality, he is no less dangerous, having advocated for both physical and sexual violence against women.