President Donald Trump ignited the ire of gun rights advocates — including many of his supporters — Wednesday when he suggested confiscating guns without due process from people believed to be mentally ill.

In a televised meeting with lawmakers, Trump told fellow Republicans that they are "afraid of the NRA," and delighted Democrats by suggesting support for stronger background checks for gun purchases, bans on assault weapons, and raising the age to purchase AR-15–style rifles to 21.

The reaction from gun rights groups was swift. Minutes after the meeting, Breitbart News had labeled the president — who was endorsed by the NRA — "Trump The Gun Grabber."

"We believe he's gone from, in his own words, the Second Amendment's best friend to the gun-grabber in chief," Michael Hammond, legislative counsel for Gun Owners of America, told BuzzFeed News.

"As soon as he becomes president, he adopts Michael Bloomberg's agenda," said Hammond, referencing the former mayor of New York City, who is a prominent supporter of pro–gun control groups.

Trump also suggested arming teachers and called for the abolishing of "gun-free zones" — proposals that are supported by the NRA and other gun rights advocates. But it was his other comments during the roundtable discussion that alarmed the president's supporters, in particular his remark that officials should "take the guns immediately from people that you could judge immediately they are mentally ill."

As the meeting went on Trump again seemed to suggest the government could ignore due process rights when confiscating weapons. When Vice President MIke Pence referenced a California law that mandates people named in restraining orders turn in their firearms, Trump interjected.

"Take the guns first, go through due process second," he said. "A lot of times by the time you go to court, it takes so long to go to court, to get the due process procedures. I like taking the guns away early."

It was a remarkable shift for the president, who has frequently touted his endorsement from the NRA, and cast himself as a supporter of gun rights and gun owners. During the presidential campaign, Trump repeatedly revved up his base with warnings that Hillary Clinton wanted to abolish the Second Amendment.

Had Trump "not ran on support of the Second Amendment," Hammond said, "he would not be president of the United States."