The head of the House Intelligence Committee is hand-delivering a letter to colleagues on Capitol Hill, demanding they not restrict the FBI’s surveillance power — and citing the recent mass shooting in Orlando as justification. The letter opposes a proposed amendment that would put an end to FBI “backdoor” searches of an NSA database of foreign intelligence without judicial oversight.

“The national security threats to the United States and its allies are greater today than at any point since 9/11. To keep Americans safe, our intelligence community needs to fully employ every tool available to it,” Rep. Devin Nunes, R-Calif., wrote in the letter obtained by The Intercept, cosigned with Rep. Lynn Westmoreland, R-Ga.

The proposed reforms would severely handicap the FBI’s investigations into events like the tragedy in Orlando, they argued. “The intelligence community would not be able to look through information lawfully collected [by the NSA] to see if Omar Siddiqui Mateen, the Orlando nightclub attacker, was in contact with any terrorist groups outside the United States.”

But there’s no indication that the reform would have posed an obstacle for the FBI’s investigation into the Orlando shooter — or that he ever communicated with anyone abroad.

Nunes and Westmoreland are pushing back against changes proposed by Reps. Zoe Lofgren, D-Calif., and Thomas Massie, R-Ky., to the House Defense Appropriations Bill currently being considered in Congress. Lofgren and Massie have offered similar widely-supported amendments in the past.

They propose to end the practice of FBI agents investigating domestic crimes conducting warrantless searches on the NSA’s database of foreign intelligence collected under Section 702 of the Foreign Intelligence Surveillance Act.

Proponents of the FBI’s ability to conduct warrantless searches on the database say it’s fine because the data was collected legally — though the surveillance was only directed at foreign targets.

But some Americans’ communications wind up in the database, too.

Critics of those warrantless searches argue that the FBI has other, reasonable options for pursuing investigations into attacks like Orlando.

Given that Mateen explicitly pledged allegiance to several terror organizations, including ISIS, Jahbat al-Nusra, and Hezbollah, getting a warrant to search his emails presumably would not have been an insurmountable problem.

The proposed change would not prevent the FBI from accessing information collected by the NSA — it would just force agents to go to a judge and demonstrate probable cause to conduct the search.

“Nothing in the Massie-Lofgren amendment would prevent the Intelligence Community from querying their database for Omar Mateen’s online communications collected under Section 702 – or under any other FISA authority for that matter,” Lofgren said in a statement emailed to The Intercept.

“The 4th Amendment has kept us safe for over 200 years. Now is not the time to abandon the Constitution,” she concluded.

Read the rest of the letter below: