They asserted that the President lacked the authority to authorize wiretaps that circumvented the Foreign Intelligence Surveillance Act.
He and others pointed out that Congress Governments had authorized wiretaps and surveillance of opponents in the 1970's and 1980's.
If that is not fast enough, the attorney general may authorize wiretaps and then seek a warrant within 72 hours.
Over the course of the investigation, he remains willing to sign court documents authorizing wiretaps.
It can also authorize wiretaps, impose travel bans, request financial information about suspects, freeze financial transactions and request the assistance of other law enforcement agencies.
But lawyers at a separate top-secret intelligence unit are the gatekeepers for foreign intelligence warrants authorizing wiretaps and other surveillance.
Erratic at best on civil liberties, he would from time to time release grand jury transcripts to the press and authorize investigative wiretaps.
FISA provides that even if Congress declares war, the president may authorize warrantless wiretaps only for "a period not to exceed fifteen calendar days."
He held in 1972 that the President may not authorize wiretaps of dissidents suspected of violent plans without a judicial warrant.
Mr. Hegde resigned on Wednesday when it was revealed that his government had authorized wiretaps on the telephone conversations of political foes in his state.