LOUISVILLE, Ky. — Donald Trump on Friday slammed Hillary Clinton as “heartless” for backing restrictions on gun ownership that he said would leave Americans in high-crime areas unable to protect themselves. He also challenged Clinton to follow his lead and release a list of potential Supreme Court nominees.

Trump’s remarks came at the National Rifle Association convention in Louisville, Kentucky. The gun rights’ organization endorsed the presumptive Republican nominee ahead of his remarks, despite Trump’s previous support for measure like an assault weapons ban that the NRA vigorously opposes.

Trump centered much of his remarks on Clinton, claiming she would seek to “abolish” the Second Amendment if elected president. He called her a “Heartless Hillary” — a new nickname for the likely Democratic nominee — for backing restrictions aimed at reducing gun deaths, saying her proposals would instead law-abiding citizens at risk from criminals.

“She’s putting the most vulnerable Americans in jeopardy,” Trump said. “That is so unfair and that is so egregious.”

Clinton has said she supports the Second Amendment but that safety measures are needed to keep firearms out of the wrong hands. She has called for expanding background checks to sales at gun shows and online purchases, and for reinstating a ban on assault weapons.

Trump backed an assault weapons ban, as well as slightly longer waiting periods for gun purchases, in a 2000 book. He’s since said such bans don’t work and has also called for making it easier for law-abiding citizens to carry guns for self-protection.

On Friday, he reiterated his call for ending “gun-free zones” and touted the list of potential Supreme Court nominees he released this week as a sign of his commitment to upholding the Second Amendment.

“I’d like to call for Hillary Clinton to put together a list also,” said Trump, predicting her potential justices would be a “day and night” difference with his.