The Congressional Research Service released a report this afternoon that says Dubya's domestic spying policy rests on what could charitably be described as shaky legal ground.

An excerpt:

While the Congressional report reached no bottom-line conclusions on whether the program is legal or not, it concluded that the legal rationale appears somewhat dubious. The legal rationale "does not seem to be as well-grounded" as the Bush administration's lawyers have suggested, and Congress did not appear to have intended to authorize warrantless wiretaps when it gave President Bush the authority to wage war against Al Qaeda in the days after the Sept. 11 attacks, the report concluded.

Bush administration lawyers quickly took issue with the report's conclusions, arguing that President Bush acted within his constitutional and statutory powers in approving the N.S.A. program.

"The president has made clear that he will use his constitutional and statutory authorities to protect the American people from further terrorist attacks," said Brian Roehrkasse, a spokesman for the Justice Department.

"As the attorney general has stated numerous times, the National Security Agency activities described by the president were conducted in accordance with the law and provide a critical tool in the war on terror that saves lives and protects civil liberties at the same time," Mr. Roehrkasse said.

But many Democrats and some Republicans said they found the doubts raised by Congressional report persuasive, pointing to it as another indication that President Bush may have overextended his authority in fighting terrorism.

Thomas H. Kean, the former chairman of the Sept. 11 commission, said he too doubts the legality of the program. Weighing in for the first time on the controversy, he said in an interview that the commission was never told of the operation and that he has strong doubts about whether it is authorized under the law.