WASHINGTON – As criticism of the National Security Agency mounts, the U.S. intelligence community is bracing for an overhaul of how it does business on a level not seen since Sen. Frank Church held hearings into intelligence abuses nearly four decades ago.

The contentious Church hearings, which held the nation spellbound with tales of attempts at assassinating foreign leaders, led to momentous reforms, including the establishment of an intelligence oversight committee.

Today’s revelations are not nearly as dramatic, but the regular drip of leaks from former NSA contractor Edward Snowden is reaching critical mass in Washington, where lawmakers of both parties are beginning to rally around the idea of reining in what they see as NSA overreaching.

“It is time for serious and meaningful reforms so we can restore confidence in our intelligence community,” Sen. Patrick Leahy, a Vermont Democrat and chairman of the Senate Judiciary Committee, said last week. “Modest transparency and oversight provisions are not enough. We need real reform.”

Leahy and Rep. James Sensenbrenner, R-Wis., are proposing a series of changes as to how the NSA operates.

While the political momentum is rising, some analysts worry that Washington will go too far and harm American intelligence capabilities at a time when al-Qaida and other terrorist groups remain a threat.

“There is well-founded concern that there may be moves to clamp additional restrictions on intelligence activities,” said Paul Pillar, a former CIA official. “The political mood at the moment is one where there is a political incentive to do something.”

Until recently, key lawmakers defended the NSA and criticized Snowden for spilling sensitive secrets. But a recent report that the NSA eavesdropped on the cellphone of German Chancellor Angela Merkel, a key American ally, as well as other foreign leaders has transformed the political climate.

The Merkel allegations have “changed the atmosphere,” said David Wise, who has written extensively about intelligence issues.

A key turning point came Monday when Sen. Dianne Feinstein, who is chairwoman of the Senate Intelligence Committee and has vigorously defended the NSA against the Snowden disclosures, expressed exasperation about the latest revelations.

“With respect to NSA collection of intelligence on leaders of U.S. allies – including France, Spain, Mexico and Germany – let me state unequivocally: I am totally opposed,” Feinstein said. “Unless the United States is engaged in hostilities against a country or there is an emergency need for this type of surveillance, I do not believe the United States should be collecting phone calls or emails of friendly presidents and prime ministers.”

The White House last week continued to deal with the fallout over monitoring Merkel’s cellphone. National Security Adviser Susan Rice and Director of National Intelligence James Clapper met with their German counterparts in Washington in what White House spokesman Josh Earnest described as part of the administration’s effort to “resolve some of the tension that has arisen out of some of the reports on surveillance activities reportedly conducted by the U.S.”

1970s revelations more dramatic

Analysts point out that the reports surfacing today are not nearly as dramatic as the charges in the 1970s, which included allegations that the CIA targeted foreign leaders for assassination. At one point, Church, an Idaho Democrat, waved a poison dart gun in front of television cameras. The hearings led to a system of congressional oversight and imposed restrictions on CIA activities.

The controversies today are about sweeping up information and the potential for trampling civil liberties – not black-bag jobs in foreign countries.

Still, the political climate is growing more ominous for the intelligence world. The specter of continued revelations from Snowden raises the stakes even further and could place more pressure on lawmakers to take action.

Lawmakers, such as Leahy and Sensenbrenner, already have proposed bills that would limit the amount of data the NSA can sweep up as lawmakers have hauled administration officials to Capitol Hill, where they had to respond to allegations that Merkel’s cellphone was tapped.

In both chambers of Congress, lawmakers have offered fixes to the domestic spying apparatus that they believe will lead to more transparency for an oversight system that largely was built out more than 35 years ago and has failed to keep up with technological advances.

Before the Merkel controversy erupted, lawmakers had focused on tightening eavesdropping rules in the United States.

Bills have been introduced to ban the NSA’s bulk collection and data-mining of Americans’ telephone and Internet records. Legislation also has surfaced to change the supersecret Foreign Intelligence Surveillance Act court, commonly known as the FISA court, which hears NSA and law-enforcement requests to spy on Americans.

Another bipartisan effort – which the White House supports – calls for creating a privacy advocate at the FISA court, a person who could argue against government requests when he or she felt it was appropriate.

Merkel case changes debate

The larger debate about the NSA’s role has been complicated by the disclosure of monitoring the calls of foreign leaders such as Merkel and reports, disputed by U.S. officials, about widespread NSA surveillance of private citizens in France, Italy and Spain.

The first leak by Snowden to the British newspaper The Guardian – which revealed that the FISA court had secretly allowed the telecommunications company Verizon to hand over a treasure trove of domestic call data – caused distress among some lawmakers. But immediate calls for changes were fairly muted. Some legislators leaped to the defense of the NSA.

Part of the restraint might have been because of the fact that lawmakers had debated and reauthorized FISA, the 1978 law regulating the intelligence courts, said Mieke Eoyang, a former Democratic aide to the House Permanent Select Committee on Intelligence. In short, while the extent of the data collection may have been surprising to the public, it didn’t surprise most lawmakers, Eoyang said.

That, however, wasn’t the case with the disclosure that the NSA was monitoring Merkel’s calls.

“When the stories started breaking about Merkel and other foreign leaders, you had members of Congress feeling like, ‘Why wasn’t I aware of this?’” said Eoyang, the national security director at centrist Democratic group Third Way. “Congress doesn’t like to be surprised.”

© 2013 USA TODAY. All rights reserved.