President Bush has said that a congressional resolution that has authorized him to use force against Iraq allows him to order spying within the United States without a warrant.
Brownback said: ''There was no discussion in anything that I was around that gave the president a broad surveillance authority with that resolution."
Specter said senators would examine that issue and other legal questions in hearings that are scheduled for early February.
Gonzales was White House counsel when Bush initiated the program; such a role could raise issues of attorney-client privilege in seeking his testimony. A message left yesterday with the Justice Department was not immediately returned.
Asked on CBS's ''Face the Nation" whether Gonzales had agreed to appear, Specter said: ''Well, I didn't ask him if he had agreed. I told him we were holding the hearings and he didn't object. I don't think he has a whole lot of choice on testifying."
Senator Charles E. Schumer, Democrat of New York, called for Gonzales's predecessor as attorney general, John Ashcroft, and Jim Comey, a former deputy attorney general, to testify at the hearings. ''It would render these hearings useless and prevent the American people from getting to the bottom of this if the administration invoked executive privilege," Schumer, a committee member, said in a statement.
Academics and others will be asked to appear. They would be in a list of witnesses ''who think the president was right and people who think the president was wrong," Specter said.
Slightly more than half of Americans, 56 percent, want the administration to obtain court approval before tapping into conversations inside the United States even if suspected terrorists are involved, according to an AP-Ipsos poll conducted last week. About four out of 10 agreed with the White House that court approval would not be necessary.
Brownback, on ABC's ''This Week," said the Senate Intelligence Committee also will hold hearings, which will be closed.
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