"If the president is right and they've gotten results from it and prevented the blowing up of targets in the United States, I have a hard time getting too concerned about it," Sen. Bob Bennett said in an interview.

It is also possible, he said, that disclosure of the president's decision to authorize the agency to monitor within the United States has harmed national security, and if that is the case, there should be an investigation into who leaked information and why it was leaked.

Sen. Orrin Hatch, who was chairman of the Judiciary Committee when Bush authorized the extraordinary surveillance measures and who also is a member of the Senate Select Committee on Intelligence, said he was not briefed on the president's orders. But Hatch said he respects the decision "to limit the scope of those who received briefings to eight out of 535 members in Congress given the sensitive nature of this matter."

Hatch said he expects that Congress will hold hearings on the National Security Agency activities, and it is best to wait for the facts to be gathered before passing judgment.

"If certain aspects of these protective efforts can be improved, or cannot be fully justified, appropriate changes should be made," he said in a statement.

Four members of the Senate Intelligence Committee, including two Republicans, have called for an investigation by the committee into the president's use of the power. And Sen. Arlen Specter, chairman of the Senate Judiciary Committee, said the program "raises very fundamental questions . . . about privacy and the Bill of Rights," and plans to hold hearings.

Beginning in 2002, Bush authorized the the agency to monitor phone conversations and e-mail traffic of citizens in the country without obtaining a warrant from a special, secret court created for such purposes under the Federal Intelligence Surveillance Act.

Hatch has said the best measures should be taken to prevent another terrorist attack, but civil liberties must also be preserved. He cautioned against resorting to partisan attacks on the matter.

The president said the surveillance was necessary to keep pace with terrorist suspects communicating with foreigners, and blasted the disclosure of the project as damaging to national security.

Bennett said Congress should investigate the source of the leak that led to The New York Times breaking the story. He said the timing raises questions of whether the material was published to harm the president.

"If in fact the leak is damaging to national security sure they ought to investigate," he said. "If the president's authority is as solid as he insists and some of these law professors agree, I would think he would have no objections to having that reaffirmed by [Congress]."

Attorney General Alberto Gonzales said Monday that Congress gave the president the surveillance authority when it passed its resolution authorizing force after the Sept. 11, 2001, terrorist attacks.

Bennett would not comment on the legal rationale.

"The question of whether or not he's warranted in doing this is now a battle between the legal experts" from prestigious universities, Bennett said. "Not being a lawyer or having attended any of those fancy universities, I'm willing to let them battle that out."