"Let me not get into any nominee, but Gonzales is an excellent human being," Mr. Hatch said. "He's done an exceptional job as White House counsel. He's brought additional stability and peace to the Justice Department. I know the president is interested in trying to find people of diversity -- he's really bent over to do that as president."

Mr. Gonzales is a longtime Bush aide and friend from Texas, and naming him could enhance the Republican Party's standing among Hispanics, one of the president's longtime political goals. Some conservatives acknowledged that they had stated their opposition to him with some delicacy to avoid provoking the White House, given Mr. Gonzales's friendship with the president.

But the swift and vociferous opposition to Mr. Gonzales reflected the intensity of concern on the right over just what kind of conservative Mr. Bush will choose, as he moves toward a decision that will go a long way toward settling any question about what kind of conservative he is, and how his presidency will be remembered.

Mr. Weyrich, while declining to disclose the specifics of a recent conversation with Ken Mehlman, the Republican Party chairman, said: "We have let the administration know through whatever channels we have that Gonzales would be an unwise appointment because of the opposition of some of the groups," some of which he said would actively oppose Mr. Gonzales, while "others like the Southern Baptists and myself would simply not help."

For many conservatives, who have seen Republican presidents nominate justices like Ms. O'Connor who then vote against them on pivotal issues, Mr. Gonzales epitomizes the fear of the unknown. But in other ways, and to some Democrats, he is very well known, confirmed by a vote of 60-to-36, along largely partisan lines, after unexpectedly contentious hearings and debate in which Democrats challenged his policies on the detention and treatment of prisoners in the administration's campaign against terror. In a 2002 legal memorandum, Mr. Gonzales characterized as "obsolete" the Geneva Conventions' limitations on questioning of enemy prisoners, and he said provisions in the conventions like commissary privileges and athletic uniforms were "quaint."

"He would face stiff opposition from liberal groups," said Nan Aron, president of the liberal legal group Alliance for Justice. "He would have to answer tough questions about his role in the administration's war on terror."

Senator Charles E. Schumer, Democrat of New York and a member of the Judiciary Committee, declined to say on Saturday how Senate Democrats might respond to a Gonzales nomination. "It's too early to tell -- we're not talking about any specific judge," Mr. Schumer said.