Last week, in a bid to clarify his historically nebulous stance on abortion, Donald Trump said that if reelected, he intends to leave abortion rights “to the states,” seemingly contradicting his prior stance in favor of a 16-week national ban. But Mary Ziegler, a law professor at UC Davis and leading abortion historian, thinks that a complete ban could be on the agenda for a future Trump administration—and the vehicle for it would be the Comstock Act, a 19th-century anti-obscenity law still on the books.