The first story on Sunday’s Last Week Tonight was, atypically, about last week’s biggest U.S. news story — Justice Samuel Alito’s leaked majority opinion striking down Roe v. Wade and the constitutional right to obtain and abortion. “And while the fate of Roe may not have been a surprise, the draft itself was still a horror show,” John Oliver said, offering one plausibly explanation for why the Constitution’s framers “left off the specific right to abortion.”

But “Alito wasn’t just deferring to the Constitution, he repeatedly cited some other notable sources, too, like 17th century jurist Sir Matthew Hale, who once described abortion as a ‘great crime,'” Oliver said. “He also argued that a husband cannot be guilty of a rape committed up on his wife, sentenced two women to death for witchcraft, and argued young women were ‘the ruin of families’ because they ‘learn to be bold’ and ‘talk loud.’ And while those believes might earn you a Netflix comedy special called Trigger This, they should absolutely disqualify you as a scholarly reference on the matter of reproductive rights.”

“We need to be able to talk about abortion like adults, because when, as now seems inevitable, this ruling becomes official, there will be immediate and devastating consequences,” Oliver argued. “And it is worth taking some time tonight to talk about a few thing: What this ruling means, how we got to this point, and where we go now. And when it comes to what this means, it’s catastrophic.”

Polls consistently show that “the majority of Americans don’t want to overturn Roe,” Jean Yi and Amelia Thomson-DeVeaux write at FiveThirtyEight. But “abortion is a thorny issue in American life. It’s not something people like to talk about, and it’s not something people know that much about.”

Oliver talked about it in great depth, and strongly advocated for abortion rights, passionately and with sometimes NSFW language. But “we may now also need to shore up all the other rights supposedly guaranteed by Supreme Court rulings, from voting rights to gay marriage, because the fact is, under the current Supreme Court, your basic rights today could become crimes tomorrow,” he argued, and that will take work and sustained commitment. “Anti-choice advocates worked really hard for a really long time to ensure that Roe would not be permanent, but the thing is, its undoing doesn’t have to be, either.”