WASHINGTON (AP) – Senate GOP leaders plan to confirm Supreme Court nominee Samuel Alito early next week after dealing with a filibuster threat from Democratic die-hards who worry that the conservative judge would swing the court too far to the right.

A final vote making the New Jersey jurist the nation’s 110th Supreme Court justice was scheduled for Tuesday morning, only hours before President Bush begins his State of the Union address to Congress and the nation, if Alito’s bipartisan supporters succeed in rounding up 60 votes to cut off debate on Monday.

Republicans didn’t seem worried, with 52 of their 55-member majority and three Democrats _ Robert Byrd of West Virginia, Tim Johnson of South Dakota and Ben Nelson of Nebraska _ already publicly supporting Alito’s confirmation as replacement for retiring Justice Sandra Day O’Connor.

A Democratic senator who plans to vote against Alito’s confirmation, Sen. Joseph Biden of Delaware, said Friday that prospects for a successful filibuster were dim and he doesn’t support the idea.

“A filibuster, I think, is not likely to occur,” Biden told CBS’ “The Early Show.” “But who knows, one man can generate a filibuster.”

Sens. Daniel Akaka of Hawaii and Byron Dorgan of North Dakota made it clear Thursday night after a second day of floor debate on Alito that they would not support a filibuster, even though Akaka was going to vote against the nominee and Dorgan was still undecided.

“Next Tuesday, a bipartisan majority will vote to confirm Judge Alito as Justice Alito,” Senate Majority Leader Bill Frist, R-Tenn., said.

As the floor debate was continuing Thursday, the leaders of the filibuster attempt _ Massachusetts Sens. Edward Kennedy and John Kerry _ were trying to drum up support in their caucus for blocking Alito.

They were counting senators like Russ Feingold of Wisconsin, Dick Durbin of Illinois and Debbie Stabenow on their side. Other senators, including ranking Judiciary Democrat Patrick Leahy of Vermont and Charles Schumer of New York, head of the Senate Democrats’ fundraising arm, did not say Thursday whether they supported the effort.

“There’s some division in our caucus,” Kennedy conceded. “It’s an uphill climb at the current time, but it’s achievable.”

Senate Democratic leader Harry Reid of Nevada offered little support.

“There’s been adequate time for people to debate,” Reid said. “No one can complain on this matter that there hasn’t been sufficient time to talk about Judge Alito, pro or con.”

Many Democrats contended that Alito’s confirmation would put individual rights and liberties in danger. The former federal prosecutor and lawyer for the Reagan administration would replace O’Connor, the court’s first female justice and the swing vote on several 5-4 rulings that maintained abortion rights, preserved affirmative action and limited the application of the death penalty.

“The president has every right to nominate Samuel Alito to the Supreme Court,” said Kerry, who called for the filibuster while attending an economic conference in Europe. “It’s our right and our responsibility to oppose him vigorously and to fight against this radical upending of the Supreme Court.”

Asked if the administration was taking Kerry’s call for a filibuster seriously, White House press secretary Scott McClellan chuckled on Friday and said: “I think it was a historic day yesterday. It was the first ever call for a filibuster from the slopes of Davos, Switzerland.”

Republicans immediately began criticizing Democrats for even considering a filibuster.

“Continuing to threaten a filibuster, even after it is crystal clear that Democrats don’t have the necessary votes to sustain their obstruction, is needless, strange and at odds with many of their fellow Democrats,” said Sen. John Cornyn, R-Texas.

Bush urged the Senate to go ahead and put the 55-year-old judge from the 3rd U.S. Circuit Court of Appeals on the Supreme Court.

Alito “understands the role of a judge is not to advance a personal and political agenda,” the president said Thursday at the White House. “He is a decent man. He’s got a lot of experience and he deserves an up-or-down vote in the Senate.”

Twenty-two of the Senate’s 44 Democrats voted against John Roberts’ confirmation as chief justice last year.

Alito may be on his way to the most partisan Senate victory for a Supreme Court nominee in years. The closest vote in modern history is Clarence Thomas’ 52-48 victory in 1991, when 11 Democrats broke with their party and voted for President George H.W. Bush’s nominee.