WASHINGTON - In the early days of the Bush administration, allegiance to the conservative debate club known as the Federalist Society was declared almost in a whisper.

A nominee for a top Justice Department post, grilled by a Democratic senator last year about his membership in the society, professed that he had no idea what its politics were.

Judicial nominees, meanwhile, scrambled to disavow positions they had taken before the society. As critics attacked its influence in the White House, members complained of McCarthyite smear tactics.

But if membership in the Federalist Society was once a source of controversy, last week it became cause for a coming-out party, as several thousand members at the group's 20th anniversary conference reveled in its growing influence in the Bush administration in the wake of the Republican-swept elections.

A three-day conference that concluded yesterday at the Mayflower Hotel in Washington looked at times less like a private law conference than a Justice Department retreat.

No fewer than 12 senior Justice Department officials - including John Ashcroft and half of his 10 top-ranking assistant attorneys general - gave speeches and attended seminars to give their decidedly conservative views about terrorism, religious freedoms and other issues.

Despite a budget of $3.2 million and nearly 30,000 members, the Federalist Society does not stake out official positions or endorse candidates.

It does not bring lawsuits or file legal briefs. What it does, organizers say, is promote dialogue about constitutional principles and the law.

Along the way, it has attracted conservative admirers throughout the Bush administration and the federal judiciary, much to the chagrin of liberal critics who say it has achieved too influential a behind-the-scenes role in governing.

Six months or so ago, said David M. McIntosh, a Washington lawyer and co-founder of the society, the society's members sometimes felt as if they were under interrogation by the Communist-hunting House Un-American Activities Committee for their beliefs.

But with wider exposure and more sympathetic ears, he said, the group sees a greater chance than ever before to influence legal policy - particularly in bringing like-minded jurists to the federal bench.