You cannot legally buy a gun online or at a gun show without passing a criminal background check in Connecticut, and you shouldn’t be able to do so anywhere else in the country, Sen. Chris Murphy says.

The Connecticut Democrat introduced a bill Wednesday that would make all private gun sales subject to the FBI’s National Instant Criminal Background Check System, as commercial sales are.

“Last year, more than 120,000 people were stopped from buying a gun because of background checks,” Murphy told a crowd gathered outside the U.S. Capitol in Washington, D.C. “But gun sales have migrated to places where background checks are not required, and we know when you tighten those loopholes, lives are saved.”

Murphy conceded during an interview before the midday press conference that while his plan had more concessions for opponents than the comprehensive background checks bill that failed in the Senate last year, the bill still has little chance of passing the Republican-controlled Congress.

Murphy said he wrote exceptions into his bill after speaking with Connecticut gun owners, who see the regulation as unnecessary and onerous.

For example, people would be allowed transfer their guns to family members, and people would be able to lend a rifle to a neighbor for hunting without needing a background check.

The president of the largest gun rights group in the state said he appreciated Murphy’s concessions, but questioned the junior senator’s larger gun-control agenda.

“It’s nice that Sen. Murphy is rethinking some of his prior positons on background checks, but I am just not sure what he is trying to accomplish,” said Scott Wilson of the 28,000-member Connecticut Citizen’s Defense League. “I understand his concerns, but people can pass a background check and that does not prevent them from committing a crime.”

Wilson noted that the shooter who killed 20 first-graders and six educators in the 2012 Sandy Hook massacre took his mother’s AR-15-style rifle from an unlocked closed, and that the shooter who killed 58 and wounded 500 in the early-October Las Vegas massacre legally owned the firearms he used.

Murphy said the bill is needed because as many as 25 percent of gun sales are estimated to take place without background checks.

“Ninety percent of Americans support expanded background checks, three-quarters of gun owners support expanded background checks, and the majority of NRA members support expanded criminal background checks,” Murphy said. “We need to make sure that when guns are sold in this country, they are only sold to law-abiding citizens.”

Murphy questioned how long the Republican majorities in the House and the Senate could oppose a bill with such popular support, especially with midterm elections approaching.

Sen. Richard Blumenthal, a co-sponsor of Murphy’s bill along with Illinois Sen. Dick Durbin, agreed.

“Let Donald Trump hear this message: We are not going away and we are not giving up,” Blumenthal told the crowd at the Capitol. “We are going to continue fighting as long as people are dying.”

The Newtown-based National Shooting Sports Foundation, a firearms industry trade association, did not have an immediate comment on Wednesday.

Lawrence Keane, the senior vice president and general counsel for the NSSF, said he had yet to review the text of Murphy’s bill.

Murphy said criminals are getting around background checks by buying firearms online or at gun shows.

“Illegal guns that are sold on the streets of Hartford and New Haven and Bridgeport are because some criminal goes to South Carolina to buy a bunch of guns at a gun show and drives them back up to Connecticut to sell them,” Murphy said.

Terrorists are doing the same thing, he said.

“Al-Qaida and ISIS are openly recruiting people in the U.S. to go to gun shows and buy guns to kill Americans,” Murphy said. “This bill says once and for all: If you are going to buy a gun in this country, just prove that you are not a criminal.”