After the failure of four gun measures in the Senate on Monday evening, a compromise proposal seeking to close the terror gap appears to be gaining bipartisan backing.

Maine Republican Susan Collins said she will introduce a compromise proposal Tuesday with support from senators on both sides of the aisle. The move will test whether Senate leaders in either party are actively working to pass a deal, or if they are calculating that, in advance of the November election, their parties are better served by leaving the status quo intact.

Collins aims to capitalize on bipartisan agreement that the terror gap should be closed — a reform that nearly every senator voted for yesterday, but one that, when considered as individual proposals, fell short of the 60 votes needed. Her plan is designed to address concerns raised about the dueling amendments offered by Democratic Senator Dianne Feinstein of California and Republican John Cornyn of Texas. Both measures attracted scant support outside their sponsors’ respective parties.

Collins on Monday delayed a roll out of her plan until Tuesday, using the extra time to assess the results of last night’s vote and gather more support.

Even as the measure gains backers, however, it faces a tough climb. Her plan will need support from Republican or Democratic leadership to win 60 votes — and such help has not been forthcoming so far.

Asked Monday night if Senate Majority Leader Mitch McConnell will allow a vote on her proposal, Collins said, ”I believe he will.” But Republican leaders and many rank-and-file members have shown limited interest in Collins’s pending bill. Cornyn, the second-ranking Senate Republican, has faulted the proposal.

Among voters, there is wide support for preventing those on the U.S. government’s terrorist watch list from buying guns: A Gallup poll conducted last week found that 84 percent of Democrats back such a measure, as do 75 percent of Republicans.

Senate Democrats forced a vote on Feinstein’s bill in part to show voters that vulnerable Republicans are still marching in lockstep with the National Rifle Association, and may not be eager to give Republicans who voted against Feinstein’s plan a chance to seek political cover via the Collins plan.

“All they care about is taking care of the NRA,” Senate Minority Leader Harry Reid, a Nevada Democrat, said at a news conference yesterday evening. Reid said New Hampshire Senator Kelly Ayotte of New Hampshire, who faces a tough reelection fight and voted for both Feinstein and Cornyn’s proposals Monday, “did everything but yoga on the Senate floor” to try to avoid choosing a side on the issue.

Amid Democratic attacks over her past opposition to expanding background checks, Ayotte is co-sponsoring the Collins plan.

“There is an opportunity for bipartisan compromise here,” she told reporters in the Senate on Monday. “We’re going to put together a good faith proposal. We have it. It makes sense.”

“How about we focus on a result instead of playing politics with this?” she said.

GOP Senator Jeff Flake of Arizona is also working with Collins. During the votes on Monday, those three Republicans pitched their plan to fellow senators, appearing to seek support from Senator Marco Rubio of Florida, who is poised to announce that he is running for reelection, and Rob Portman of Ohio, who faces a tough campaign. To create the necessary momentum, the Collins team is also trying to recruit Senators who don’t go before voters this cycle.

“Once you get a critical number, not just Republicans who are up for reelection, you can get a vote and hopefully get it passed,” Flake told The Trace.

Democratic Senators Heidi Heitkamp of North Dakota, who votes with Republicans on gun issues, and Joe Donnelly of Indiana also support the Collins effort, aides said. Senator Joe Manchin, a West Virginia Democrat who championed a background check bill in 2013, is still reviewing the plan but has been supportive.

Bill Nelson, a Florida Democrat, and Lindsey Graham, a South Carolina Republican, are also working on the compromise. Collins told reporters she revised her proposal at their behest.

Supporters of the compromise measure hope to address concerns their colleagues had that Feinstein’s proposal, which allowed the Attorney General to bar people suspected of terror ties from purchasing guns, would infringe on due process rights. Democratic critics of Cornyn’s measure, which required the Justice Department to show probable cause within three business days to block a terror suspect from buying a gun, said it would impose an impossibly high burden.

While Feinstein’s proposal was based on barring anyone on a terror watch list from buying a gun, Collins says she would limit the ban to the smaller, federal “no-fly” and “selectee” lists, which is comprised of people subject to extra screening before boarding a plane. Collins’s plan would also create a mechanism that would alert the FBI if someone who had been on either list in the previous five years tried to buy a gun. It would not bar the suspect from making the purchase.

Republicans have repeatedly said that votes on gun regulations are a distraction following the shooting in Orlando, Florida, on June 12. “We’d like to actually talk about the real cause of that attack, and that is a terrorist attack on our own soil, and why the policies both in the Middle East and here at home are inadequate to deal with the threat of homegrown radicalization,” Cornyn told Politico.

Senior Democrats offered a variety of messages regarding the Collins plan — though all suggested the measure is unlikely to succeed.

On Monday night, Reid said it was “interesting” that few Democrats had seen the measure, noting it “has been kind of secret.”

Reid and New York Senator Charles Schumer argued that McConnell and other Republicans will ultimately block Collins’s bill from receiving a vote, rendering bipartisan negotiations moot.

Schumer also told reporters that “from what I understand there are some problems with the proposal.” He argued that the plan would not have prevented Orlando gunman Omar Mateen from buying weapons since it applies only to the no fly and extra screening lists. While Mateen was twice placed under federal investigation, no indication has emerged that Mateen was on those lists.

Democrat Robert Menendez of New Jersey said Collins’s proposal would apply to so few people “that it would be be fig leaf” covering just a sliver of the roughly 800,000 people — both Americans and foreign citizens — on the larger terror watch list. Collins herself told reporters that there are about 2,700 people combined on the no-fly and selectee lists who could be barred from gun purchases under her plan.

“Unless it changes, it is not something I could support, or that I think most Democrats could support,” Menendez said.

[Photo: AP/J. Scott Applewhite, File]