Connecticut’s U.S. senators are once again playing a lead role in pushing to close a loophole in the federal law that allows unlicensed or private sellers to transfer a firearm without requiring the buyer to undergo a background check.

The proposal makes sense. It would save lives. Polls show its goal of universal background checks enjoys overwhelming support, even among gun owners.

But it has little chance of passage.

The “Background Check Expansion Act” would extend the existing law to require background checks for the sale or transfer of firearms from one unlicensed private party to another, whether the transaction takes place online, at a gun show, or through a sale out of a home. Background checks, required of sales by licensed dealers, block the transfer of guns to individuals with a history of criminal activity or domestic violence.

Private sellers would need to visit a licensed firearms dealer to run the necessary background check before they could sell a gun.

Connecticut already has such stringent requirements, but without a common-sense federal rule to match, guns purchased by unsavory individuals can still find their way into the state. Chicago has extremely tough gun laws, but that has not stopped guns purchased elsewhere and illegally sold on the streets from finding their way into the hands of gang members.

“More than 3,000 people have been shot in Chicago so far this year — more than 500 fatally,” lamented Sen. Dick Durbin, D-Illinois, during a press conference held in Washington, D.C., on Wednesday to announce the bill’s introduction.

Also in attendance were Sens. Richard Blumenthal of Connecticut and Catherine Cortez Masto of Nevada, who are among 28 cosponsors of the Senate bill, all Democrats.

“Gun violence found over 22,000 attendees of a concert on the Las Vegas Strip. It found the State of Nevada, and I am devastated to say it found me,” said Cortez Masto, referencing the Oct. 1 massacre in which a single gunman murdered 58 people and injured hundreds more using assault weapons trained on a concert crowd.

“As a gun owner, I am keenly aware of the serious responsibility of owning firearms. We must work to keep guns out of the hands of the seriously mentally ill, people with a history of violence, criminals, and terrorists,” she said.

Since the Vegas massacre, another 2,500 Americans have been shot, nearly 800 killed.

An estimated 25 percent of gun sales are done legally without background checks due to the loophole. No one is claiming that closing the loophole would stop all gun violence. The Vegas killer had no criminal history. But it would save lives. In any event, it makes no sense to allow a means to lawfully circumvent background checks.

Sen. Chris Murphy of Connecticut deserves due credit for his persistence on this issue. He was a U.S. representative for the district that included Newtown when a deranged young man used an assault rifle to slaughter 20 school children and six adult educators at a school there in 2012. He has been fighting for sensible gun reform laws ever since.

At the press conference, Murphy pointed to data showing that in states with universal background checks 47 percent fewer women die by way of gun violence than in jurisdictions without them.

Last year, after a man opened fire in an LGBT nightclub in Orlando, killing 49 people, Murphy led a 15-hour filibuster to demand action on gun control. Republicans responded by allowing votes, but the bills failed, including one to expand background checks.

That seems likely to be the case again. And even if by some miracle it won Senate approval, it would almost certainly get nowhere in the House. In any event President Trump, who would have to sign the bill, has pledged full allegiance to the National Rifle Association and its unwillingness to entertain any stricter requirements on the purchase of guns.

By including reasonable exceptions to the background requirement — exempting the loaning of firearms for hunting or sporting activities, the gifting to family members, or transfers between law enforcement officers — the bill anticipates the excuses Republican and Democratic gun supporters have given for blocking universal background checks.

No matter, most still won’t support it. The $10.6 million the gun lobby spent last year alone backing pro-gun politicians and attacking any lawmaker who crosses them has proved effective.

So why try?

“We are going to keep this issue before the American people,” Durbin said.

That’s reason enough. In time, the will of the people will prevail.

The Day editorial board meets with political, business and community leaders to formulate editorial viewpoints. It is composed of President and Publisher Timothy Dwyer, Executive Editor Izaskun E. Larraneta, Owen Poole, copy editor, and Lisa McGinley, retired deputy managing editor. The board operates independently from The Day newsroom.