WASHINGTON — Amid renewed calls for urgent action on gun control, members of Congress are weighing potentially bipartisan ideas to curb gun violence after mass shootings in El Paso, Texas, Dayton, Ohio, and Gilroy, California,over the last two weeks have left nearly three dozen people dead.

The legislative proposals under consideration include stronger background checks, “red flag” laws that prevent those threatening harm to themselves or others from buying or possessing firearms and bans on large-capacity magazines or assault-style firearms.

House and Senate lawmakers are back home in their districts for August recess, however, and are expected to stick to that schedule given that Senate Majority Leader Mitch McConnell, R-Ky., has ignored Democrats’ calls to bring the Senate back for an emergency session to take up House-passed legislation to tighten background checks on gun buyers.

The Senate's absence through Labor Day could diminish any momentum for action, resulting in Congress not passing any legislation at all — as was the case after numerous mass shootings over the last decade such as the 2012 Newtown mass shooting, the 2017 Las Vegas shooting and 2018 shooting in Parkland, Florida.

“I think that we have to take advantage of this moment of opportunity because once it passes, we go back to the status quo,” said Michael Siegel, professor at Boston University’s School of Public Health, who has studied how state gun laws affect gun violence.

A study Siegel conducted of state gun laws and their effects from 1991 to 2016 found that universal background checks, red flag laws and bans on gun possession for those who have committed violent misdemeanors would have the greatest effect in reducing gun deaths.

Democrats are calling on McConnell to take up a bill the House passed in February that would establish new background check requirements for firearm transfers between unlicensed people. But only eight House Republicans voted in favor of the bill, and its Senate outlook is uncertain.

Sen. Pat Toomey, R-Pa., said he wants to revisit a similar universal background checks measure he co-sponsored with Sen. Joe Manchin, D-W.Va., that fell six votes short of advancing in 2013. Of the four Republicans who backed the proposal at the time, only Toomey and Sen. Susan Collins, R-Maine, still serve in the Senate.

After speaking with President Donald Trump and with McConnell after the shootings, however, Toomey said calling the Senate back to Washington immediately could backfire for those seeking legislative action.

“If we force a vote tomorrow, then I think the vote probably fails and we may actually set back this whole effort," Toomey said during a conference call with reporters on Monday. "So for a successful outcome, which is what I want, then I think you work towards developing the coalition and the consensus so that you actually get the right outcome.”

Everytown for Gun Safety President John Feinblatt warned that Republicans will face angry voters at home in their districts if they wait to take action.

“August recess is going to be a very rough month for Republicans because I think what you are going to see is grassroots activists in every district, particularly districts that are up in 2020,” he said. “We have 300 grassroots events already scheduled for just this week. So that gives you a little bit of taste of what August is going to be like.”

Monday morning, Trump initially called for “strong background checks” on Twitter, saying such legislation could be paired with “desperately needed immigration reform.” In later remarks at the White House, he also called for red flag laws and for legislators to reform mental health laws.

Experts, however, have said there's no evidence that people with mental illness are at a higher risk for committing gun violence.

"It is important to note that the overwhelming majority of people with mental illness are not violent and far more likely to be victims of violent crime than perpetrators of violence," the American Psychiatric Association said in a statement this week. "Rhetoric that argues otherwise will further stigmatize and interfere with people accessing needed treatment. Individuals can also be emboldened to act violently by the public discourse and divisive rhetoric."

Democrats expressed skepticism that Trump will commit to these plans given that he initially voiced support for background checks after the Parkland shooting in 2018 only to make more modest proposals after discussions with the NRA.

McConnell has tasked three committee chairmen to “reflect” on what Trump raised as possible legislative solutions, and said they should engage in bipartisan discussions of potential solutions “without infringing on Americans’ constitutional rights.”

Sen. Lamar Alexander, R-Tenn., chairman of the Senate Health, Education, Labor and Pensions Committee, said he is “ready to do more, especially on background checks, to identify those who shouldn’t have guns.” Senate Judiciary Committee Chairman Lindsey Graham, R-S.C., said that he’s working on a red flag law with Sen. Richard Blumenthal, D-Conn. Other Republicans such as Sen. Mike Braun of Indiana and Sen. Rob Portman, R-Ohio, also have advocated stronger background checks.

“I think you're seeing some significant movement within the Republican Party on this issue,” said Feinblatt. “And I think you're going to hear more voices, particularly voices among Republican senators like Cory Gardner or Thom Tillis, both of whom are up in 2020, and their constituents expect them to protect themselves and their families.”

Schumer said in a statement this week that “red flag” laws — which the NRA suggested this week it would be open to — are not a sufficient solution to the problem of gun violence and called for passing universal background checks.

“We Democrats are not going to settle for half-measures so Republicans can feel better and try to push the issue of gun violence off to the side," he said. "Democrats in the Senate will seek to require that any [red flag] bill that comes to the floor is accompanied by a vote on the House-passed universal background checks legislation.”

Some Democrats are pushing for Congress to revive the assault weapons ban that President Bill Clinton signed into law, which expired in 2004 — including Clinton himself. But some reviews of the law, including a report commissioned by the National Institute of Justice, found that the ban had mixed results, and gun policy experts have suggested a prohibition on large-capacity magazines could also help reduce shooting deaths.

“It was too easy [under the assault weapons ban] for manufacturers to make simple modifications to guns so they weren’t subject to the ban and then sell that part as an aftermarket accessory," said Cassandra Crifasi, assistant professor at Johns Hopkins’s Bloomberg School of Public Health. "I think it would be far more effective to focus on limiting access to large capacity magazines that allow an individual to fire lots of rounds without having to reload.”

Siegel added, “You could have a pistol that has 30 rounds in it. As far as I'm concerned, that's an assault weapon. I don't want somebody with 30-round magazines and a pistol coming into a public place. You can do a lot of damage in a short amount of time.”

Laura Dugan, associate chair at University of Maryland’s Department of Criminology and Criminal Justice, said that while no single policy will end all mass shootings, measures can at least curb them.

“The harder we make for somebody to be able to spray bullets across the room people, the better it is, the better it'll be," she said. "Will it end mass shootings? Probably not. Will it save lives? Probably."

Recent surveys have shown that an overwhelming majority of the public supports background checks — including gun owners. A 2018 Quinnipiac University poll, for example, found that 97 percent of gun owners support universal background checks.

Some experts hope that Republican discussion of potential reforms could make a difference this time.

“I think that the more people who own guns speak out against the type of gun laws that we have, I think [it] will also be really helpful, because hearing liberal people speak out about what we need is more gun laws isn't really changing anyone's minds," Dugan said. "We need people who are strong gun advocates say, 'No more.'"