U.S. citizen Omar Mateen’s murder of 49 people at a Florida nightclub on Sunday appears to have doomed a legislative push to rein in warrantless surveillance with defeat of an amendment that twice passed by wide margins.

The amendment offered by a diverse group of Republican and Democratic lawmakers to ban two types of “backdoor” surveillance on Americans was defeated in a 222-198 vote on Thursday.

Last year, the House passed the measure in a 255-174 vote after an even more lopsided 293-123 victory in 2014. After both votes, the amendment was not considered by the Senate and was axed in budget deals brokered by more hawkish congressional leaders.

The pivot in the House against enhancing privacy protections in the face of mass surveillance is one of the first congressional repercussions of the most deadly mass shooting in modern U.S. history.

The once-popular two-page amendment would have prohibited funds in the annual defense spending bill from being used by the NSA and CIA to foist surveillance-facilitating product redesigns on tech companies or to perform warrantless searches of U.S. internet records collected under Section 702 of the Foreign Intelligence Surveillance Act.

The amendment’s primary sponsors, Reps. Thomas Massie, R-Ky., and Zoe Lofgren, D-Calif., said the measure would merely restate what the Fourth Amendment requires and protect the country by keeping encryption from being weakened to the benefit of criminals and others.

Mateen’s citizenship featured prominently in debate on Wednesday ahead of the vote, with opponents of the reform saying it would needlessly tie the hands of U.S. authorities.

Rep. Chris Stewart, R-Utah, claimed the amendment was motivated by “false and irresponsible allegations of government spying on Americans.”

Stewart, a member of the House intelligence committee, said “if this amendment were in effect today, the intelligence community would be unable to query the 702 database for the names of the Orlando nightclub attacker, for his wife or even the nightclub itself.”

House Judiciary Committee Chairman Bob Goodlatte, R-Va., made similar claims.

“This amendment prohibits the government from searching data already in its possession collected lawfully under Section 702 of FISA to determine whether Omar Mateen was in contact with foreign terrorists overseas,” Goodlatte charged.

He added, appearing to pick at the precise amendment wording: “Despite the characterization by proponents of the amendment that a search could occur if the government has obtained a FISA or criminal probable cause based order, the exception does not in fact authorize such a query.”

There are two primary NSA surveillance programs under Section 702. “Upstream” collection siphons communications directly from cables, switches and routers that make up the internet’s backbone. The PRISM program takes records directly from companies like Facebook and Google.

Section 702 authorizes surveillance of foreign intelligence targets living overseas, but when communications of U.S. citizens are collected they can be stored and searched without a warrant.

In 2015, intelligence agencies including the NSA and CIA – but notably not including the FBI – targeted an estimated 94,368 individuals under Section 702, according to a transparency report issued in response to whistleblower Edward Snowden’s 2013 disclosures.

An estimated 4,672 search terms were used last year to target U.S. persons – a term that includes citizens and permanent residents – and 23,800 queries were performed concerning a known U.S. person, according to the report.

It’s possible the number of search terms and queries affecting U.S. persons is much higher, as the FBI investigates terror plots within the U.S.

Rachel Brand, a member of the presidentially appointed Privacy and Civil Liberties Oversight Board, said at a hearing last month the FBI doesn't track the number of queries it performs because the information is contained in a database that contains other records, which can be searched as a preliminary step in investigations.

Brand testified that the FBI does not use "upstream" intercepts collected under Section 702, a legal provision set to expire late next year.

Republican Rep. Ted Poe of Texas, who joined Massie and Lofgren in speaking in favor of the amendment, pushed back against criticism Wednesday, though it was as futile as privacy advocates speaking against the Patriot Act after 9/11.

“[Section] 702 was designed to go after the bad guys overseas, but it’s being used to collect communications of Americans in America without a search warrant under the Fourth Amendment,” he tsked. “[The amendment] says the Constitution must apply to Americans, and fear tactics from the other side, I’m sorry, don’t change the facts.”

After the vote, Massie told U.S. News he found it "somewhat ironic that the Democrats hoped to use the event in Orlando to erode the Second Amendment while Republicans have gone against the Fourth Amendment.”

Massie says he’s considering splitting the “backdoor” amendment in two, as the ban on forced encryption vulnerabilities found little spoken opposition – though he disagrees with Goodlatte’s claim the measure could have barred access to Section 702 records even with a court order.

The libertarian lawmaker says the timing isn't right now, but that some future revelation about abuse of surveillance powers, perhaps from a whistleblower, could give reformers new momentum ahead of next year's debate on whether to renew Section 702.