Attorney General William Barr drew stern objections from Democrats when he told Congress he believes “spying” occurred on the 2016 Trump campaign. He doubled down by unleashing U.S. Attorney John Durham to investigate the origins of the FBI’s Russia investigation.

Liberals, mindful of leaker Edward Snowden’s revelation that the government had hoovered up Americans’ metadata under the last Republican president, are worried about the potential for warrantless surveillance under the current Republican president, whom Bernie Sanders accuses of being an “authoritarian leader.” Amid all this acrimony, Republicans and Democrats should realize we all need to better understand and control the Foreign Intelligence Surveillance Act, a law under which intelligence and law enforcement agencies can ensnare conversations between unwitting Americans and foreigners.

With confirmation hearings looming for the replacement of Dan Coats as national intelligence director, Democrats and Republicans alike should use the opportunity to explore the potential for abuse of FISA and other surveillance programs. In early 2009, Department of Justice officials acknowledged that broad authority granted by the previous Bush Administration had resulted in government “overcollection” of domestic communications by the National Security Agency. Under President Barack Obama, the FBI, CIA, and other agencies’ searches of names or phone numbers of U.S. citizens in surveillance metadata exploded from 9,500 in 2013, to 30,355 in the election year of 2016.

To be sure, it is common for the federal government to surveil foreign targets located abroad under FISA authority. Such international surveillance does not violate the Fourth Amendment, which forbids warrantless and “unreasonable” searches and seizures within the United States. However, when a foreign call is known to involve American citizens and legal residents located in the U.S. (defined in law as “U.S. persons”), who are suspected of acting as foreign agents, a court order authorizing the surveillance must be obtained from one of 11 judges serving on a secret FISA court.

Still, the incidental, warrantless collection of conversations from U.S. citizens while surveilling foreigners is common. Under the provisions of FISA, the identities of these Americans must usually be masked when they are read by intelligence agencies and other executive branch officials. But an official may “unmask” or request the identification of the U.S. person in a call if the official requires it to assess that intelligence.

Relying on that principle, in a 12-month period between 2015-2016, the Obama administration unmasked 9,217 U.S. persons. And former U.N. Ambassador Samantha Power was that administration’s Barry Bonds of unmasking: Serving nearly all of Obama’s second term, Power — or, as she reportedly testified to Congress, someone using her name — requested unmaskings of Americans more than 260 times.

Power’s record of unmasking is striking compared to that of her predecessor, John Bolton. Though accused by then-Sen. Joe Biden in 2005 of spying on policy opponents at the State Department, once acting ambassador, Bolton reportedly unmasked only three people.

Why was Power (a diplomat, not an intelligence official) so unrestrained in her unmaskings? Or did someone use or perhaps misuse her name?

Glints of light show through this dark glass. Late in her tenure, Power was busy countering the Trump transition team, which had generated sparks with its vocal disagreement with the Obama administration’s U.N. vote to abstain from condemnations of Israeli settlements on Palestinian territory. Were these unmaskings Power’s way of keeping track of a disagreement over foreign policy or political payback?

You might think that being on the receiving end of this treatment, the Trump administration would take steps to curb unmasking. Quite the contrary. Large-scale unmasking continues under the Trump administration, with 2018 seeing 16,721 unmaskings, an increase of 7,000 from the year before.

As mutual recriminations fly between Trump supporters and the intelligence community, there is potential for generating more heat than light. In the middle of this fray, we should remember that only a fraction of surveillance conducted under FISA is politically contentious. But if the perception solidifies that FISA is a tool for political witch hunts, it will harm the integrity of our political system, while jeopardizing public support for truly valuable intelligence gleaned from surveillance of foreign threats.

If the nation is to trust that the system is not being abused, there must be a public reckoning. Department of Justice Inspector General Michael Horowitz will soon release his findings of an internal investigation of the handing of the Russia investigation, in addition to Durham’s investigation. While unmasking is not a specific mandate of these investigations, either one might cast light on how unmasking has been used or abused.

Periodic revelations from one-off investigations alone, however, will not be enough to restore public confidence in FISA. Congress needs to enact strong reforms in keeping with its constitutional duty to monitor surveillance programs.

Concern about warrantless surveillance of Americans has previously united civil liberties activists from Left to Right to endorse and promote the passage of Lee-Leahy , the Senate version of the USA Freedom Act. It would end bulk collection of Americans’ data, strengthen protections and transparency, and curb surveillance overreach. Passage of Lee-Leahy would go a long way toward protecting Americans against political unmasking.

If Congress steps up to the plate, the law can keep Americans safe both from foreign threats and unjustified, intrusive surveillance.

Gene Schaerr, a Washington, D.C.-based attorney and former Associate Counsel to President George H.W. Bush, serves as general counsel to the nonpartisan Project for Privacy and Surveillance Accountability.