Congressional Democrats and gun control advocates say Donald Trump’s comment that “Second Amendment people” could thwart Hillary Clinton’s judicial nominees, amounts to, in the words of one, an “assassination threat.”

The GOP presidential nominee was discussing Clinton appointing Supreme Court justices if she is elected president at a rally in North Carolina Tuesday.

“If she gets to pick her judges, nothing you can do, folks,” Trump said. “Although the Second Amendment people, maybe there is, I don’t know.”

The former congresswoman who was nearly killed alongside a federal judge reacted to that.

“Donald Trump might astound Americans on a routine basis, but we must draw a bright red line between political speech and suggestions of violence,” said former Arizona Rep. Gabrielle Giffords in a statement with with her husband, Mark Kelly. “Responsible, stable individuals won’t take Trump’s rhetoric to its literal end, but his words may provide a magnet for those seeking infamy. They may provide inspiration or permission for those bent on bloodshed.”

“It must be the responsibility of all Americans — from Donald Trump himself, to his supporters, to those who remain silent or oppose him — to unambiguously condemn these remarks and the violence they insinuate,” Giffords and Kelly said. “The integrity of our democracy and the decency of our nation is at stake.”

Giffords was shot in the head in Tucson, Ariz., in 2011. Six people were killed in the shooting, including John M. Roll, Arizona’s chief federal judge.

Sen. Chris Murphy, D-Conn., tweeted that the remarks amounted to an “assassination threat.”

“This isn’t play. Unstable people with powerful guns and an unhinged hatred for Hillary are listening to you, @realDonaldTrump,” Murphy added. Murphy is one of the leading gun control proponents in Congress.

Don’t treat this as a political misstep. It’s an assassination threat, seriously upping the possibility of a national tragedy & crisis.

— Chris Murphy (@ChrisMurphyCT) August 9, 2016

Fellow Democratic Sen. Elizabeth Warren of Massachusetts also responded on Twitter, alleging Trump, “makes death threats because he’s a pathetic coward who can’t handle the fact that he’s losing to a girl.”

Rep. Eric Swalwell, D-Calif., called on the Secret Service to investigate Trump’s comment as a threat.

Donald Trump suggested someone kill Sec. Clinton. We must take people at their word. @SecretService must investigate #TrumpThreat.

— Rep. Eric Swalwell (@RepSwalwell) August 9, 2016

Jason Miller, a senior communicators adviser for the Trump campaign, said in a statement, “It’s called the power of unification — 2nd Amendment people have amazing spirit and are tremendously unified, which gives them great political power. And this year, they will be voting in record numbers, and it won’t be for Hillary Clinton, it will be for Donald Trump.”

But the Clinton campaign said Trump was suggesting violence.

“This is simple — what Trump is saying is dangerous,” Clinton campaign Manager Robby Mook said. “A person seeking to be the President of the United States should not suggest violence in any way.”

Trump’s latest statements will likely have more congressional Democrats calling on their GOP colleagues to rescind their support for the presidential nominee.

Democratic Pennsylvania Senate candidate Katie McGinty called out her opponent, incumbent GOP Sen. Pat Toomey, in a tweet, saying, “Enough is enough.”

Sadie Weiner, the spokeswoman for the Senate Democrats’ campaign arm, said in a statement, “The only thing more appalling than Donald Trump are the Republican Senators and Senate candidates who continue to stand with him.”

Some Republicans have already said they cannot support Trump. Sen. Susan Collins, R-Maine, on Monday became the fourth Republican senator to announce she would not vote for Trump. She is not up for re-election in November.

Collins did have a more charitable view of Trump’s “Second Amendment people” comment.

“I’ve been very critical of Donald Trump, but I actually don’t think that’s what he was saying. I think he was suggesting that the second amendment advocates across the country might be able to come together to pressure the Senate to reject her nominee should she become president,” Collins told MSNBC.

“That is how I interpreted it,” Collins said. “But it is an example of Donald Trump’s looseness with language that can lead to interpretations such as the one put out by Secretary Clinton’s camp.”

Niels Lesniewski contributed to this report.Contact Bowman at bridgetbowman@rollcall.com and follow her on Twitter at @bridgetbhc.