WASHINGTON — President Donald Trump on Wednesday once again backed tighter background checks for gun purchases, but said he wants to be careful that closing what he calls “loopholes” doesn’t clear the way for more gun control.

Speaking to reporters as he departed the White House for Kentucky, the president said he considers gun violence a public health issue and is considering ways to make background checks more strict. But he also said, “You’re on that slope and all of a sudden nobody has any legal protection,” adding, “Our Second Amendment will remain strong.”

Told the “slippery slope” argument is a National Rifle Association talking point, Trump said, “It’s a Trump talking point.”

The rhetorical whiplash came after gunmen opened fire in El Paso, Texas, and Dayton, Ohio, leaving more than 30 people dead. In the days following the mass shootings early this month, Trump said he was eager to implement “very meaningful background checks” and told reporters there was “tremendous support” for action. He dismissed that very same “slippery slope” thinking, which he attributed to the NRA, saying, “I don’t agree with that.”

But he also has acknowledged that his core supporters support gun rights, highlighting the challenge of balancing the politics of gun control ahead of the 2020 elections.

On Tuesday, Trump signaled he was backing away from supporting changes to the system. Speaking to reporters, he noted that “a lot of the people that put me where I am are strong believers in the Second Amendment,” and he suggested he worries about blurring the contrast between Republicans and Democrats on the issue.

“We have to be very careful about that,” he said.

It was a change in tone. He said Tuesday that while the current system has “sort of missing areas and areas that don’t complete the whole circle,” it is overall “very, very strong” — even though federal law only requires background checks for guns sold through licensed firearm dealers.

The waffling drew anger from Democrats, including Senate Minority Leader Chuck Schumer, who said if Trump is serious about action he should call on Senate Majority Leader Mitch McConnell to put a House-passed bill on background checks up for a vote.

“These retreats are heartbreaking, particularly for the families of the victims of gun violence,” Schumer tweeted.

Republicans have refused to take up several Democratic-backed gun control bills that passed the House, and historically they have opposed many efforts to strengthen the nation’s gun laws.

Sen. Chris Murphy, D-Conn., who spoke with Trump last week, said the president expressed support then for working across the aisle “to come up with a background checks bill that can pass the Senate and save lives.” While he said he would wait to hear from Trump again directly, he compared the episode to Trump’s flip-flop on background checks following the Parkland, Florida, school shooting after intervention from the NRA.

“It’s time for Republicans and President Trump to decide whose side they’re on,” Murphy said in a statement. “Are they going to stand with the 90% of Americans who want universal background checks, or are they going to once again kowtow to the desires of the gun lobby?”

Trump, who has reversed course on gun issues throughout his adult life, had insisted when pressed by skeptical reporters earlier this month that this time would be different because the composition of the House and Senate had changed.

But a senior White House official pushed back on the notion that Trump was backing away from support for legislative changes, noting that Trump has repeatedly voiced a desire to get something done.

The person, who spoke on the condition of anonymity to discuss internal deliberations, said the White House’s policy and legislative affairs teams have been discussing potential options, in addition to ongoing conversations with members of Congress led by Eric Ueland, the director of legislative affairs.

They also said “meaningful background checks” remain on the table, even after Trump spoke again by phone Tuesday with NRA chief executive Wayne LaPierre.

LaPierre tweeted the two had discussed “the best ways to prevent these types of tragedies,” and called Trump “a strong #2A President.”

While two Democrats on the Hill described talks with the White House as largely stalled, others said White House officials have been engaged in continued conversations with Democratic and Republican lawmakers. That includes staff-level conversations with Murphy’s office since he spoke with Trump last Sunday, according to one Senate staffer.

“The White House has been very responsive to our office,” said Steve Kelly, a spokesman for Republican Sen. Pat Toomey of Pennsylvania, who has long pushed a bipartisan expanded background check bill with Democratic Sen. Joe Manchin of West Virginia. “We’ve had ongoing conversations, at the staff level, with the White House regarding background checks both last week and this week.”

Republicans have been trying to build support for more modest measures, including so-called red-flag bills from Sen. Lindsey Graham, R-S.C., and Sen. Marco Rubio, R-Fla., that would allow friends and family to petition authorities to keep guns away from some people. But those efforts are also running into trouble from conservatives, who worry about due process and infringing on gun owners’ rights.

Meanwhile, NRA spokeswoman Amy Hunter said the group “has always supported efforts to keep firearms out of the hands of criminals and the dangerously mentally ill” and “appreciates the president’s desire to find logical ways of accomplishing that goal.”

“However, even the most ardent anti-gun advocates would concede expanded background checks would not have stopped any of the recent high-profile shootings,” she said. “In order to reduce gun deaths, we must address the root causes of crime.”