WASHINGTON – President Bush ignored questions yesterday about whether he will dismiss his top political adviser, Karl Rove, over Mr. Rove’s apparent role in disclosing the identity of a CIA operative, Valerie Plame, though a White House spokesman said later that the president continues to have confidence in his longtime aide.

The swirling controversy riveted much of official Washington yesterday. As Democrats stepped up their attacks on the embattled political guru, Republicans and Mr. Rove’s own lawyer sharpened their defense.

The chairman of the Republican National Committee, Kenneth Mehlman, accused Democrats of unleashing a partisan smear campaign. Mr. Rove’s attorney, Robert Luskin, trained criticism for the first time on the Time magazine reporter whose notes touched off the current imbroglio, Matthew Cooper.

During a morning meeting with Prime Minister Lee of Singapore, Mr. Bush did not respond to shouted questions about whether he would fire Mr. Rove. At a briefing yesterday morning, the White House press secretary, Scott McClellan, refused to address a question about whether the president continues to have confidence in Mr. Rove, who was given the title of deputy chief of staff earlier this year. By early afternoon, however, Mr. McClellan offered a different, if somewhat generic, reply: “Any individual who works here at the White House has the president’s confidence. They wouldn’t be working here if they didn’t have the president’s confidence.”

As he did on Monday, Mr. McClellan brushed aside a series of questions from reporters about the accuracy of the White House’s previous statements denying Mr. Rove’s involvement in the leak.

Democrats staked out varying positions on Mr. Rove’s alleged misconduct.

Senator Kerry of Massachusetts was among the most strident. At a press conference to discuss homeland security funds, he answered a question about the controversy by saying forcefully that the president should sack Mr. Rove.

“The White House’s credibility is at issue here, and I believe very clearly, Karl Rove ought to be fired,” the 2004 Democratic presidential nominee said.

As Mr. Kerry laid out his critique of the White House, Senator Clinton, who was standing nearby, nodded repeatedly. Asked for her reaction, she said simply, “I’m nodding.”

When asked by The New York Sun whether Mr. Rove should be fired, or, as some have suggested, have his security clearance revoked, Mrs. Clinton demurred.

“It’s up to the White House. I want to wait and see what the White House does,” the former first lady said.

New York’s senior senator was not nearly so reserved. Senator Schumer summoned reporters to the Senate radio and television gallery yesterday afternoon for a briefing on his actions regarding the continuing inquiry into Mr. Rove’s conduct. Mr. Schumer announced that he was sending a letter to Mr. Bush, asking the president to repeat his statement last year that he would dismiss anyone found to be involved in leaking.

“This is an administration that has been very, very strong on keeping secrets secret,” Mr. Schumer said. “I am asking the president to reaffirm that he wishes to get to the bottom of the Plame leak and to dismiss those involved, even if that person should be his longtime associate Karl Rove.” In his letter, the senator also called on the president to order Mr. Rove to make a public statement about his involvement in the leak.

Mr. Schumer said the White House’s silence signaled that the administration’s promises to cooperate with a continuing criminal investigation were wavering.

“It seems the kind of open cooperation that the White House and the staff were giving is now being pulled back,” he said.

A special prosecutor, Patrick Fitzgerald, is investigating how Ms. Plame’s name and employment at the CIA appeared in the press in the summer of 2003. A syndicated column written by Robert Novak indicated that two administration officials said that a former ambassador who had criticized the president’s statements about Iraq, Joseph Wilson IV, was sent to investigate the country’s nuclear procurement efforts in Africa, at the urging of his wife, whom Mr. Novak described as a CIA analyst. At the time, Ms. Plame was still designated as an undercover operative. The Justice Department opened an inquiry into the leak and later turned the politically sensitive matter over to Mr. Fitzgerald, who is the chief federal prosecutor in Chicago.

Mr. McClellan has said Mr. Fitzgerald asked the White House to refrain from public comment until the probe is complete.

When asked why the White House should defy the apparent request from the prosecutor, Mr. Schumer said: “This is not an ordinary situation. Karl Rove is in a very important position. We’re at a crucial time in this republic right now. There are so many issues swirling that it would serve the public to answer these questions.”

Mr. Schumer, who termed the leak “a dastardly deed,” stopped short of calling for Mr. Rove’s firing or resignation.

“I’m not ready to go that far at this point,” the senator said.

Another Democrat, Senator Biden of Delaware, came close to endorsing Mr. Kerry’s call for dismissal. He told CNN that if news accounts about Mr. Rove’s involvement proved true, “At a minimum, that was incredibly bad judgment, warranting him being asked to leave.”

Most Republican senators remained mum about the case. In response to a reporter’s question, Senator Sessions of Alabama described Mr. Rove as “a solid guy.”

“I’m a big supporter and believe that when the dust settles, there won’t be anything there that indicates any intent to do wrong by Karl Rove,” Mr. Sessions said.

In a statement, Mr. Mehlman, the GOP chairman, said Democrats were kowtowing to radicals in their party.

“It’s disappointing that once again, so many Democrat leaders are taking their political cues from the far-left, MoveOn wing of the party. The bottom line is Karl Rove was discouraging a reporter from writing a false story based on a false premise, and the Democrats are engaging in blatant partisan political attacks,” Mr. Mehlman said.

In an interview with the Sun, Mr. Luskin, Mr. Rove’s attorney, echoed that assertion. He said the political aide was simply trying to discourage Time from reporting Mr. Wilson’s apparently inaccurate claims that Vice President Cheney or his staff arranged the Africa trip.

Mr. Luskin said the Time reporter, Mr. Cooper, gave Mr. Rove “a promise that the stuff would not be used, not simply not attributed.”

“I don’t think you can read that and say what he was trying to do was he was encouraging Time to [expose Ms. Plame],” Mr. Luskin said.

“If he was, he wouldn’t have imposed double-super-secret background,” the lawyer said, referring to Mr. Cooper’s own description of the conversation in a note to his editors.

Mr. Luskin said Time’s article on the subject was unfair because it suggested that the White House was engaged in a “war” against Mr. Wilson and because the story implied Mr. Rover was a source, even though it did not name him.

“It is sourced in a way any informed person speculating would know Karl is one of those few people,” the attorney said.

Mr. Luskin said he did not questions Mr. Cooper’s sincerity but found it odd that after the special prosecutor demanded that the Time correspondent identify his source, he nearly went to jail rather than identify Mr. Rove.

“This source came pre-burned,” the lawyer said. “There’s some irony to professing to go to extraordinary lengths to protect the source that you had already abused months before.”

An attorney for Mr. Cooper, Richard Sauber, said Mr. Luskin’s critique was puzzling and unjustified.

“I can’t imagine what that means,” Mr. Sauber said. “I believe that the contemporaneous documentation and the testimony of Matt and others will be fully supportive of and consistent with his published article.”

A political analyst at the University of Virginia, Larry Sabato, said it was notable that Messrs. Kerry and Biden came out strong against Mr. Rove, while Mrs. Clinton was more reserved. All three Senate Democrats are considered possible presidential candidates in 2008.

“She doesn’t have the same needs these other candidates like Kerry and Biden do. She’s already in with the activists. She doesn’t need to prove a thing,” Mr. Sabato said.

The analyst said Mr. Kerry’s anger toward Mr. Rove is derived from last year’s presidential race.

“It’s personal with Kerry,” Mr. Sabato said. “Rove beat him like a drum in 2004.This is a chance for revenge, and a chance to revive his fortunes, perhaps, with the Democratic activist corps.”