The question of Roberts' membership in the society — an influential organization of conservative lawyers and judges formed in the early 1980s to combat what its members said was growing liberalism on the bench — emerged as a vexing issue at the start of another week of meetings for President Bush's nominee on Capitol Hill.
Although no Democrats have publicly threatened to filibuster his nomination, they have said they're concerned that not enough is known about Roberts' personal and legal views. Questions about where he stands on a range of issues, including abortion, likely will be front-line matters at his confirmation hearings later this summer.
Roberts, nominated by Mr. Bush last week to replace retiring Justice Sandra Day O'Connor, was asked by a reporter about the discrepancy during a morning get-acquainted meeting with Sen. Dianne Feinstein, D-Calif.
He smiled but didn't reply.
"I don't think he wants to take any questions," Feinstein interjected during the session with photographers and reporters that was part of the meeting in her office with the Supreme Court nominee.
"No, no, no thanks," Roberts added.
Several news organizations, including The Associated Press, reported immediately after his nomination that Roberts had been a member of the Federalist Society. The AP and others printed corrections after the White House said later that Roberts doesn't recall ever belonging to the group.
Feinstein said she didn't ask him about whether he belonged to the Federalist Society. "It's not a dispositive question, in my view," she said. "It would be interesting to know what the answer is because he said he can't remember."
The Washington Post reported Monday that it had obtained from a liberal group a 1997-98 Federalist Society leadership directory listing Roberts, then a partner in a private law firm, as being a steering committee member in the group's Washington chapter.
Roberts has acknowledged participating in Federal Society events and giving speeches for the organization.
But on Monday, presidential press secretary Scott McClellan said, "He doesn't recall ever paying dues or being a member."
Whether he's a member or not shouldn't matter, said Sen. John Cornyn, R-Texas.
"Obviously it wasn't central in his life. But it's not like being a member of the Communist Party," Cornyn said after meeting Roberts. "The Federalist Society is an organization that hosts debates from people with a lot of different viewpoints. I think serves a very useful purpose for lawyers and people interested in these viewpoints. But I don't think that should be a limiting factor at all."
Roberts was on Capitol Hill on Monday for a fourth day of private meetings with senators who will sit in judgment of his nomination as Democrats began seeking documents he may have authored while working for two Republican presidents.
The Senate Judiciary Committee is looking at starting hearings the week of Aug. 29 or after the Labor Day holiday in order to put Roberts on track to be confirmed before Oct. 3, the start of the new Supreme Court term.
Roberts worked in the Reagan White House counsel's office from 1982-1986. He also was principal deputy solicitor general, a political appointment in the administration of the first President Bush.
Some records already are available to the public at the presidential libraries of Ronald Reagan, in Simi Valley, Calif., and George H.W. Bush, in College Station, Texas. Others have yet to be cleared for security and personal privacy by archivists and, under law, by representatives of the former administrations and the current president.
The Senate Judiciary Committee has yet to ask for such material for its hearings. But some Democrats, including Sen. John Kerry of Massachusetts, have urged the White House to release "in their entirety" any documents written by Roberts.
Citing privacy and precedent, Fred D. Thompson, the former Tennessee senator guiding Roberts through the process on behalf of the White House, said Sunday the Bush administration does not intend to release everything. Attorney General Alberto Gonzales appeared more open to considering such requests.
McClellan warned senators against even making such requests.
"We hope people wouldn't make such requests that they know are considered out of bounds and that can't be fulfilled because of those privacy issues," he said.