Liberal groups tried Friday to debunk the "popular opinion" that only a terrible showing by Clarence Thomas at confirmation hearings next week can doom his Supreme Court nomination. But President Bush predicted Thomas would win approval.

Bush said after a private meeting with the nominee at the White House, "I'm more convinced than ever that I have appointed the right man to the Supreme Court. I expect and hope that he will be confirmed."The president also taped a radio address for nationwide broadcast on Saturday as part of his effort to boost Thomas' chances.

Meanwhile, a coalition of groups opposed to Thomas said they still have a fighting chance to defeat the nomination. "Going into the hearings, this is very do-able," said Ralph Neas of the Leadership Conference on Civil Rights. "You can't lose the battle before the hearings begin."

Neas said more than 60 of the Senate's 100 members are uncommitted. "There's always a strong presumption in favor of the nominee but it's a rebuttable presumption," he said.

Thomas, a black federal judge nominated to replace retiring Justice Thurgood Marshall, the only black justice in the court's history, is expected to face tough questioning from the 14-member Senate Judiciary Committee, especially its eight Democrats.

His record as chairman of the federal Equal Employment Opportunity Commission and as head of the Department of Education's civil rights division likely will be the focus of numerous questions.

Thomas should be judged on his record, not on how well he does in answering the committee's questions, said Nan Aron of the Alliance for Justice.

And Wade Henderson of the National Association for the Advancement of Colored People, which opposes the nomination, said Thomas' "record of public performance" shows he "doesn't have a commitment to the protection of all persons."

Judith Lichtman of the Women's Legal Defense Fund said Thomas is not likely to be treated as gently as Supreme Court Justice David H. Souter was during his confirmation hearings last summer.