Senator Schumer, for his part, seemed today to take on the role of mediator between Mr. Leahy and the White House. On Sunday, Mr. Schumer — who first floated Mr. Mukasey’s name with the White House as a potential Supreme Court nominee four years ago — praised Mr. Mukasey as a potential “consensus nominee.” Today, he said he had told Mr. Fielding that the White House would have to resolve Mr. Leahy’s concerns.

“Chairman Leahy’s concern is genuine,” Mr. Schumer said in an interview. “He strongly defends the prerogatives of the committee. I stressed that to both Fielding and Mukasey. It would be much better for everyone concerned if they could reach an agreement.”

The White House is trying to cast the Mukasey confirmation as urgent and is calling on the Senate to put him in place at the Justice Department before lawmakers leave for their next recess on Oct. 8. In private, top aides to Mr. Bush are calculating that Democrats will not want a messy confirmation fight.

And most Democrats reacted with caution today. Several, like Senator Russell D. Feingold of Wisconsin, said Mr. Mukasey would have to prove that he is independent of Mr. Bush and can repair the damage they say was done to the department by Mr. Gonzales, who many Democrats regarded as a crony of the president.

Image Michael B. Mukasey, a United States District Court judge, swore Mayor Rudolph W. Giuliani into office in January 1994. Credit... Mark Lennihan/Associated Press

Others, like Senator Joseph R. Biden Jr. of Delaware, sounded surprised by what they regarded as an unusual White House overture. Mr. Biden said he was “pleased that President Bush put aside his old habits and picked an outside professional to nominate as attorney general, rather than a member of his own circle.”

With just 16 months left in his administration, Mr. Bush can ill-afford a nasty confirmation fight, and the White House had been extremely concerned about finding a consensus nominee — so much so that it found itself trying to fend off criticism not only from the left, but also the right.