The investigation into who leaked information about a National Security Agency secret wiretapping program on potential terror suspects needs to focus on the motivation behind the leak, a Democrat on the Senate Judiciary Committee said Sunday.
"There are differences between felons and whistleblowers, and we ought to wait 'til the investigation occurs to decide what happened," Sen. Charles Schumer, D-N.Y., told "FOX News Sunday."
The Justice Department on Friday opened an investigation into who leaked the information about the program, sparking debate over its threat to national security and presidential powers versus civil liberties.
The program, first revealed Dec. 16 by The New York Times, has used surveillance to review phone conversations and e-mails inside the United States without court warrants since after the Sept. 11, 2001, terrorist attacks.
President Bush defended the program on Sunday, saying it is necessary and legal to prevent future terrorist attacks.
"It's seems logical to me that if we know there's a phone number associated with Al Qaeda or an Al Qaeda affiliate, and they're making phone calls, it makes sense to find out why," Bush said during remarks to reporters after visiting wounded service members in San Antonio. "They attacked us before, they'll attack us again if they can."
Bush said the program has measures in place to limit its surveillance and "if somebody from Al Qaeda is calling you, we'd like to know why."
"This is a limited program designed to prevent attacks on the United States of America and, I repeat, limited," he said. "We're at war with an enemy that wants to hurt us again and the American people expect the commander in chief to protect them and that's exactly what I intend to do."
Bush has cited his constitutional powers and a congressional resolution after the Sept. 11 attacks to justify his approval of the program.
But Bush's decision to allow the secret wiretapping program is questionable, Schumer said.
"The president thought that there was a problem, instead of coming to the people and saying he needs changes in the law; he just did it on his own," Schumer said . "It calls into question the way the president and the vice president change things."
Sen. Mitch McConnell, R-Ky., said he welcomes the investigation, adding that members of Congress were briefed on the program and didn't reject it.
"Thank goodness the department is investigating who is leaking this information that could threaten our safety," McConnell told "FOX News Sunday." "We need new techniques in the wake of 9-11."
More information surfaced on Sunday about the program in a New York Times report that said White House officials attempted to get approval for the secret wiretapping program after a top Justice Department official rejected parts of it in 2004.
James Comey, the acting attorney general, would not approve parts of the program in March 2004 because he had concerns about its legality and supervision.
Two presidential aides asked for help from then-Attorney Gen. John Ashcroft, who was recovering in a Washington hospital after being treated for pancreatitis. The report shows that Ashcroft also had concerns. It is unknown whether the aides, White House Chief of Staff Andy Card and then-White House counsel Alberto Gonzales, persuaded him to agree or if the White House bypassed his approval.
Some parts of the program were suspended in 2004 until the Justice Department could audit it, which reportedly found no abuses of the wiretapping authority.
Congress is expected to focus on the issue of presidential power versus civil liberties early in 2006, as Sen. Arlen Specter, R-Pa., plans to hold hearings in January.
Schumer sent a letter Sunday to Specter requesting current and former administration officials be called as witnesses and suggesting that they avoid any attempt to use executive privilege to prevent testimony. Some officials include Comey, Ashcroft, Gonzales and Card.
The White House said that the program was "reviewed regularly and approved by top officials including those at the Justice Department."
But Schumer and other critics say that while the president needs tools to fight the War on Terror, other factors need to be reviewed to make sure there is a balance between security and liberty.
"When you want to shift balance, [you] must have open debate and rules that are set," Schumer said.
The investigation needs to focus on finding out who leaked the information, McConnell said.
"We are talking about intercepts with people who are talking internationally and planning another 9-11," McConnell said. "I applaud the Justice Department for beginning it."
The information may have been leaked to the media because they didn't agree with the program, Schumer said.
Supreme Court Justice nominee Samuel Alito may face tough questions about the program in his upcoming Senate confirmation hearings, which are set to begin on Jan. 9.
"The revelation about the NSA leaks means that the Supreme Court will play a very important role," Schumer said. "There are serious questions to be asked. We'll see where Alito comes down."
McConnell said he believes Alito will be confirmed in a "respectful hearing."
"We expect him to do extremely well at the hearings," McConnell said.
FOX News' Chris Wallace and Molly Henneberg contributed to this report.