The Senate Judiciary Committee's Republican leader rebuffed the White House appeal for a rapid confirmation of Samuel A. Alito Jr. for the Supreme Court and said the nominee's hearing will not take place until January.

The White House has been eager for a quick confirmation to provide the administration a political victory after a string of setbacks and to prevent liberal critics of the conservative appellate judge from having more time to dig through his record and build opposition. But Chairman Arlen Specter (R-Pa.) displayed his independent streak, saying senators need sufficient time to review Alito's 15-year record as a judge.

"It couldn't be done," Specter said of the White House's push for a confirmation vote by Christmas. "We have to do it right, we can't do it fast." The committee hearing will start Jan. 9, he said, with a targeted Senate confirmation vote on Jan. 20.

The announcement came as liberal activists and some Democrats continue to look for gaps in Alito's armor, acknowledging that his confirmation is likely in the GOP-controlled Senate unless they find a troubling incident or a compelling narrative that plausibly paints him as outside the political mainstream.

"There are differences in this [Democratic] caucus as to how conservative he is," Sen. Barack Obama (D-Ill.) said, adding that his party cannot hope to block Alito unless it is united against him and able to lure a few moderate Republicans.

For now, the Senate's Democratic leaders and their allies are portraying Alito as the choice of a weakened president deferring to his party's right wing, which forced the withdrawal of the previous nominee, Harriet Miers, the White House counsel. But senior Democratic aides acknowledged they have yet to determine which of Alito's rulings and writings to highlight.

Liberal groups have publicized a few of Alito's roughly 300 opinions, which they say reflect a narrow view of individual rights and congressional authority. But they say they have many more decisions to examine, and welcomed the extra time.

The White House put the best public face on the setback. "There is tremendous confidence in Chairman Specter doing the enormously difficult work of leading the Judiciary Committee through a confirmation process," spokesman Steve Schmidt said.

Sen. Lindsey O. Graham (R-S.C.), addressing the notion that liberals will have time to mount a campaign against Alito, said: "Anybody who wants to blast this guy over the holiday season, before he's had a chance to speak, is going to come out bad in the public eye."

Senate Democrats generally agree that their only hope of blocking Alito is through a filibuster, in which 41 of the 100 senators can use endless debate to keep a matter from reaching a vote. That would allow Democrats to lose no more than four of their 45 members (which includes a liberal independent), assuming all 55 Republicans oppose the effort.

The White House has moved quickly to introduce Alito to several Democrats from Republican-leaning states, the party members considered the most likely to resist a filibuster.

"I think it will be very, very hard for red-state Democrats to vote against this nominee because he is so qualified," said Sen. John Thune (R-S.D.), who defeated then-Democratic leader Thomas A. Daschle (S.D.) a year ago. Nor can these Democrats plausibly argue that Alito is ideologically unfit, Thune said, because his conservative beliefs largely match those of the senators' constituents.

But Senate Republicans, taking no chances, are trying to persuade Democrats to abandon the filibuster idea by saying it is bound to fail one way or another. Republicans have revived talk of a "nuclear option," in which they would change Senate rules to ban judicial filibusters. The proposed rule change could not be filibustered, and thus would require only 51 votes to be adopted.

In May, seven Democrats and seven Republicans -- the "Gang of 14" -- reached a pact that would effectively bar a filibuster unless they agreed a nomination involved "extraordinary circumstances." The group met yesterday, and most members said they are keeping open minds on Alito.

But two GOP members -- Graham and Mike DeWine (Ohio) -- signaled they would not tolerate a filibuster. That leaves the group with the slimmest possible margin of sustaining a nomination, assuming the other 12 members differ with Graham and DeWine.

Graham said in an interview that he did not know whether the gang's other Republicans would allow a filibuster to stand. But overall, he said, "the appetite for letting filibusters go on . . . is far less now" among Republicans than it was in May.

"I think a filibuster is unlikely unless Alito blows the hearings," said Marshall Wittmann, a senior fellow at the Democratic Leadership Council and former aide to Sen. John McCain (R-Ariz.), a Gang of 14 member. "Unless you have a thermonuclear reason, it's very difficult to go nuclear." From what is known about Alito's record so far, Wittmann said, it appears "we are dealing with someone who is very, very conservative, but not outrageously so."

One Democratic aide said the odds now favor Alito's confirmation, but party leaders will not be intimidated by the GOP's "nuclear option" threat.

Some conservative strategists say Senate Democrats blundered by using a parliamentary tactic Tuesday to force the chamber temporarily into a closed session to discuss prewar intelligence in Iraq. If Democrats can employ obscure rules to manipulate the Senate, the conservatives contend, they undermine their ability to say the nuclear option is an outrage.

Democratic strategists scoffed at the idea, saying the public will not believe that Democrats have abused the system when Republicans control the House, Senate and White House.

Appellate court judge Samuel A. Alito Jr. waits to meet with U.S. senators during his round of courtesy calls as President Bush's most recent nominee to the Supreme Court.