The NRA, which opposes the legislation sponsored by senators Patrick Toomey, a Republican, and Joe Manchin III, a Democrat, declined to comment.
Advisers to Senate Majority Leader Mitch McConnell, said he would not bring any gun-control legislation to the floor without widespread Republican support.
Trump has waffled, current and past White House officials say, between wanting to do more and growing concerned that doing so could prompt a revolt from his political base.
Even some supporters of the Manchin-Toomey bill, which would expand background checks to nearly all firearm sales, say it is unlikely to pass.
“I don’t think the President or his Republican allies are going to become out of nowhere advocates of aggressive gun control,” said Matt Schlapp, who leads the American Conservative Union and is a close ally to Trump.
Trump has focused on guns extensively since the shootings, calling lawmakers and surveying aides about what he should do, outreach that began on Sunday evening.
White House officials say there have been a series of meetings on a response, convened by acting chief of staff Mick Mulvaney, including a session Tuesday morning. The President has discussed with aides the idea of a Rose Garden bill-signing ceremony for gun-control legislation, a notion that seems premature to many in the West Wing.
Trump also asked lawyers about what he could enact through an executive order, officials said.
“He seems determined to do something and believes there is space to get something done this time around,” said Senate Judiciary Committee chairman Lindsey Graham, a Republican, who said he had spoken to Trump “four or five times” since the shooting.
“The President has a pretty commonsense point of view. He’s never been a sports or gun enthusiast. But he is more determined than ever to do something on his watch.”
Manchin said Trump called him at 6.30am on Monday and that the two spoke again on Tuesday, when Trump said he wanted legislation before September, when the Senate is scheduled to return.
Trump did not express explicit support for the Manchin-Toomey bill but asked a range of questions. Most of the recent mass shootings were carried out with guns purchased legally.
“He was inquisitive, wanting to know why it hadn’t happened. He wanted to know all about it,” Manchin said. “I told him we couldn’t get enough Republicans to help us.”
Manchin said he told Trump that he would need to back any gun-control legislation or it would fail again. Those comments were mirrored by almost a dozen Republicans and White House aides.
“If you don’t stand up and say, ‘This is a piece of legislation I support,’ we’re not going to get enough cover to have Republicans stand tall. They won’t be able to do it,” Manchin said.
On Tuesday, Trump outlined some NRA concerns in a second call with Manchin. “We talked about that,” Manchin said. “I told him, we don’t expect the NRA to be supportive. Mr President, in all honesty, when you did the bump stocks, they weren’t for you. They were against that, too. You didn’t take any hit on that.”
In March, the administration administratively banned bump stocks, the devices used to make semi-automatic rifles fire rapidly like machineguns.
A White House official said Trump had asked some advisers and lawmakers this week about whether the NRA had enduring clout amid an internal leadership battle and allegations of improper spending, as well as what his supporters would think of the bill.
The Washington Post reported this week that LaPierre sought to have the NRA buy him a $6 million mansion in a gated Dallas-area golf club after the shooting at Marjory Stoneman Douglas High School in Parkland, Florida, in which 17 students and staff members were killed.
Toomey said he has spoken to the President at least three times since the weekend shootings. He declined to elaborate on the conversations, although he stressed that Trump hasn’t specifically endorsed the bill. Their conversations have been more general, he said, but Toomey noted that they had been “encouraging” and “very recent”.
“I will just tell you generally the President is open-minded about this,” Toomey said.
Some measures – such as a ban on assault weapons – have been ruled out, White House officials and legislative aides say. Recent polls indicate a majority of Americans support some form of a ban on assault rifles, though there is a large partisan divide and fewer than half of Republicans support such measures.
“There’s no political space for that,” Graham said. “So I don’t think he’s going to go down that road.”
Trump was vague about what he would do in his comments Wednesday, and current and former White House officials said he is often ambivalent on what he should do after shootings.
After the Parkland shooting, Trump expressed support for background checks for gun purchases and greater police power to seize guns from mentally disturbed people. But he faced significant resistance from the NRA and Republicans and abandoned the ideas.
On Air Force One after the October 2017 shooting in Las Vegas that left 58 dead, Trump said he wanted to enact a law to keep such shootings from happening again and would question others for ideas but did not have specific proposals.
After shootings, Trump regularly would poll aides about what measures would have political support, but if they did not gain backing, he was not inclined to lead the charge.
“He would not be blocking it, but he’s not going to be the one forcing it to happen,” this official said.
Some of the President’s more moderate friends and donors have pressed for more-robust gun-control measures. But Trump has also told advisers that he cannot lose any members of his “base.”
“Republicans are headed for extinction in the suburbs if they don’t distance themselves from the NRA. The GOP needs to put forth solutions to help eradicate the gun violence epidemic,” said Dan Eberhart, a Republican donor.
Democrats, while generally supportive of red flag laws, questioned how much congressional efforts would actually help states – particularly conservative ones with Republican governors – enact them. Senate Minority Leader Charles Schumer said on Wednesday that Democrats would demand a vote on legislation expanding background checks that had already passed the house and is opposed by the Trump administration in tandem with any Senate vote on red flag laws.
“The question is, what difference can the federal government make in what is largely a state decision?” said Democratic Senator Chris Murphy, one of the most vocal advocates of gun control in Congress.
“I’m all for federal action on extreme risk protection orders. I’m just not sure it’s going to move the needle.”
The Washington Post