Sen. Chris Murphy said Thursday that talks aimed at closing loopholes in the gun buyer background check system failed because Texas Sen. John Cornyn wouldn't budge enough on sharpening the definition of commercial gun seller.

Cornyn and Murphy, D-Conn., declared Wednesday they had hit an impasse and had abandoned talks that began about two months ago.

"The good news is, John Cornyn is not the only Republican senator interested in talking," Murphy told reporters at the Senate, emphasizing that while "Cornyn negotiated in good faith… where we ended up just was not better than current law."

Murphy has been pushing for tougher gun restrictions since the 2012 Sandy Hook Elementary shootings in Newtown, Conn.

Cornyn is a former member of the Senate Republican leadership, and an NRA-backed gun rights advocate. He authored a law that improves data collection for the system used to prevent criminals and people with a history of domestic violence or serious mental illness from buying a gun illegally.

"He was always an important partner because getting John's buy-in, we thought, was a way to get to 60" votes needed to overcome a filibuster, Murphy said, conceding that without Cornyn on board, that task will be much harder.

"If you brought a commercial background checks bill to the floor, it would have Republican votes. I just don't know that it would have 10," Murphy said. "So, we're talking now with a handful of people including Lindsey Graham and Pat Toomey. Don’t know if we’ll get to the finish line but it’s good to have multiple potential partners."

The Murphy-Cornyn talks were focused on a loophole that allows gun buyers to sidestep the background check system by purchasing from unlicensed dealers.

"That was a limited reform to begin with," Murphy said, expressing frustration that even a goal he and other gun control advocates view as modest remains elusive.

In March, the House voted to require background checks on almost all gun purchases, closing loopholes that exclude sales at gun shows and by any unlicensed seller.

That bill has stalled in the Senate.

Cornyn had said that he hoped to strike a deal with Murphy to expand the definition of commercial gun dealer while keeping family-to-family gun transfers and other informal transactions exempt from the background check requirement.

The end of the Cornyn-Murphy talks leaves the fate of any new background checks bill unclear.

"We were negotiating over expanding the definition of who is engaged in the business of selling, and so that was a limited reform to begin with," Murphy said. "We had trouble coming to a conclusion on exactly how we would word an expansion of those that were engaged in the business."

For Cornyn, it also may relieve pressure from especially ardent Second Amendment advocates who decried his willingness to seek any sort of compromise.

The Gun Owners of America, which has looked down on the National Rifle Association as soft, has sent at least two email blasts this week to would-be donors, accusing Cornyn of "quietly making a deal with the rabid anti-gunner, Chris Murphy, to pass universal background checks."

"If John Cornyn, who represents the state of TEXAS, is already considering stabbing gun owners in the back, then you know that we’re truly in a DIRE situation," an email read.

The Second Amendment Foundation chastised Cornyn for expressing openness to expanding the definition of who has to register for a federal license to sell, import or manufacture firearms.

"The Cornyn/Murphy scheme – more dealers will mean more background checks, which will result in less crime – has been tried before," an article on the group’s website says. "Obama tried to tighten the screws and force more people into getting FFLs in 2016. It didn’t work then. Cornyn and Murphy should know that now."

Private sellers are not required to conduct a background check on buyers.

"Texans who want to buy a gun will still have the private sale option even if the [Cornyn-Murphy] negotiations hadn’t broken down," said Gyl Switzer, executive director of the gun violence prevention organization Texas Gun Sense.

Cornyn, elected in 2002, has been involved in numerous efforts to bolster the federal background check system.

He introduced and pushed through the Fix NICS Act in the aftermath of a 2017 massacre at a church in Sutherland Springs, Texas, when a gunman killed 26 people. The shooter had a history of violence that made him ineligible to legally buy a gun.

But the Air Force had failed to report the red flags to the National Instant Criminal Background Check System (NICS), the database gun dealers use to vet buyers.

The law is intended to avert such problems in the future by requiring federal agencies to report all disqualifying records of people prohibited from buying or owning a gun.

After the El Paso and Midland-Odessa shootings in 2019, Cornyn introduced the RESPONSE Act (Restoring, Enhancing, Strengthening, and Promoting Our Nation’s Safety Efforts), which he said would help prevent future attacks in part by creating task forces to prosecute unlicensed firearms dealers.

In March, Cornyn was part of a bipartisan group, five senators from each party, that re-introduced the NICS Denial Notification Act, which would require alerts within 24 hours to state and local police when a would-be gun buyer fails a background check.