AUGUSTA, Maine — Maine’s U.S. senators are backing a bipartisan bill that would block people on two government watch lists from buying guns.

The proposal from U.S. Sen. Susan Collins, a moderate Republican from Maine, could go to a vote this week, but it faces obstacles from the left and right in a paralyzed chamber, with two influential senators — a Republican and a Democrat — criticizing it Monday.

It still may represent the Senate’s best chance for action after last week’s shooting, in which 50 people died at a gay club in Orlando, Florida. A round of votes Monday blocked Republican and Democratic proposals to impede gun sales to terror suspects and expand background checks.

On Tuesday, Collins was set to unveil a compromise bill that would give the U.S. Department of Justice the authority to deny sales of guns to people who are on two government watch lists: the no-fly list or the selectee list.

“Essentially, we believe that if you are too dangerous to fly on an airplane, you are too dangerous to buy a gun,” Collins said Tuesday afternoon during a news conference in Washington, D.C.

Those lists include about 2,700 Americans and 109,000 people worldwide, according to Collins’ office. The proposal also would allow U.S. citizens and holders of green cards to appeal denials.

It includes a five-year “look-back” provision that notifies the FBI if someone on the government’s broader central terrorist watch list, which contains information on more than 1 million people, buys a gun.

That final provision may have flagged a gun purchase by Omar Mateen, the Orlando shooter who was investigated by the FBI for extremist Islamic leanings before the shooting. Mateen was not identified as a public threat in background checks conducted as part of his employment process as a security guard.

Collins’ proposal won support Tuesday from a bipartisan group of senators, including Angus King, I-Maine. It attempts to thread a needle between proposals from Sen. Dianne Feinstein, D-California, and Sen. John Cornyn, R-Texas, which on Monday didn’t get the necessary 60 votes to advance.

Feinstein’s amendment would have blocked people on terrorist watch lists or suspected of terrorism from getting guns or explosives. Cornyn’s would have allowed the government to delay sales to suspected terrorists for three days. To block the sale entirely, they’d have go to court to show probable cause.

The National Rifle Association opposed Feinstein’s proposal, which it said “provides almost limitless discretion to Obama administration officials to deny the Second Amendment rights of law-abiding Americans.”

The American Civil Liberties Union had a similar stance on both, hitting Feinstein’s proposal for using “vague and overbroad criteria” without “due process protections” and Cornyn’s for using the “error-prone and unfair” watch list system as a starting point.

But Cornyn and Feinstein criticized Collins’ proposal Monday, after language had been circulated to senators.

Cornyn said the bill’s biggest problem is that the right to appeal the government’s decision comes after a denial, according to POLITICO. He called that “kind of a fundamental line for a lot of Republicans.”

On the Senate floor, Feinstein argued Collins’ proposal was “not enough to close the loophole that creates this terror gap and allows terrorists to buy guns.”

But Collins said Senate Majority Leader Mitch McConnell, R-Kentucky, promised he’d allow a vote on the amendment, perhaps this week. Sen. Heidi Heitkamp, D-North Dakota, a backer of the effort, said her Democratic colleagues “are ready to get something done.”

“We don’t know yet what that count’s going to be,” Heitkamp said. “We’ll have to do the legwork that happens anytime you have something like this.”

Michael Shepherd

Michael Shepherd joined the Bangor Daily News in 2015 after three years as a reporter at the Kennebec Journal. A Hallowell native who now lives in Augusta, he graduated from the University of Maine in...