WASHINGTON -- In the 10 weeks since he was nominated to replace Justice Sandra Day O'Connor on the U.S. Supreme Court, Judge Samuel A. Alito Jr. has been praised by his supporters as a "lawyer's lawyer" who takes each case as it comes and denounced by critics as an ideologue who would move the court dramatically to the right.

	Judge Samuel Alito Related article Abortion, individual rights on agenda for Alito hearings

Today, after private rehearsals known as "murder boards," Judge Alito finally will speak for himself at confirmation hearings before the Senate Judiciary Committee, where he has been warned to expect even more intensive questioning than Chief Justice John G. Roberts Jr. received.

It isn't just that Judge Alito has a longer record on the bench than Chief Justice Roberts and that he would replace a perennial swing vote who was also a supporter of a constitutional right to abortion, a concept Judge Alito criticized as a lawyer in the Reagan administration. Senators also want to press Judge Alito about his views of presidential power in light of the revelation that President Bush ordered the National Security Agency to eavesdrop on American citizens without a court order.

But no matter how much Washington may be hanging on Judge Alito's words, those words probably will be less important in the end than two numbers -- 55, the size of the Republican majority in the Senate, and 14, the number of senators from both parties who have ruled out a filibuster of Supreme Court nominations except in "extraordinary circumstances."

Democrats may succeed in delaying a committee vote on Judge Alito past Jan. 17, the date contemplated by committee Chairman Arlen Specter, R-Pa. But defeating the nomination -- or derailing it with a filibuster -- is a problematic proposition regardless of what Judge Alito says in his testimony.

All 10 Republicans on the Judiciary Committee -- including Sen. Specter, an abortion-rights supporter who plans to question Judge Alito closely on that issue -- are expected to vote for the nominee. Even if the committee's eight Democrats all voted no, the nomination would be recommended to the full Senate.

Under current Senate rules, which some Republicans want to change, it takes 60 votes to cut off debate on a judicial nomination. Democrats have 44 seats and often can rely on the vote of Independent Sen. Jim Jeffords of Vermont. Alito opponents also hope that Judge Alito's past pronouncements on abortion -- especially a 1985 application for a promotion in the Reagan Justice Department in which he said "I personally believe" that the Constitution does not protect abortion -- might induce a handful of "pro-choice" Republican senators to desert his cause.

But that assumes Democrats would vote as a bloc to maintain a filibuster, which is unlikely. Yesterday, two Democratic members of the Judiciary Committee -- Sens. Dianne Feinstein, D-Cal., and Charles Schumer, R-N.Y. -- raised the possibility of a filibuster if Judge Alito gave unsatisfactory answers. But Sen. Robert Byrd, D-W.Va., who was conservative enough to be considered for a Supreme Court appointment by President Richard Nixon, has discouraged speculation about a filibuster. Mr. Byrd is one of seven Democrats in the so-called Gang of 14 who agreed last May that judicial nominations would be filibustered only in "extraordinary circumstances."

That suggests an uphill battle for Alito opponents even if the nominee made a bad impression in the hearings, said Michael Comiskey, a political scientist at Penn State University's Fayette campus and the author of "Seeking Justices: The Judging of Supreme Court Nominees."

"If the Democrats had even 47 or 49 seats, they could sustain a filibuster against Alito because I can imagine them getting three or four Republican votes if it were perfectly clear [after the hearings] that Alito opposed abortion rights," Mr. Comiskey said. "But with 44 it will be difficult."

As for "extraordinary circumstances," a term that is not defined in the Gang of 14 agreement, Mr. Comiskey was skeptical that enough senators would put the Alito nomination in that category.

Mr. Comiskey said Judge Alito's confirmation wasn't a foregone conclusion because the nominee, a 15-year veteran of the Philadelphia-based 3rd U.S. Circuit Court of Appeals, has a longer paper trail than Chief Justice Roberts. He served only two years as a federal appeals court judge before being named to the high court.

The Alito paper trail includes several hundred opinions the judge has written or joined on the 3rd Circuit and 93 documents from his days as lawyer in the Reagan administration.

Alito critics, including the liberal groups People for the American Way and the Alliance for Justice, say that the paper trail leads inescapably to the conclusion that Judge Alito is hostile to individual rights. They cite studies like one by professor Cass R. Sunstein of the University of Chicago Law School that concluded that "when there is a conflict between institutions and individual rights, Judge Alito's dissenting opinions argue against individual rights 84 percent of the time."

The Bush administration and Judge Alito's supporters counter that critics have "cherry-picked" decisions that support their caricature of the judge as a conservative activist while overlooking rulings in which he favored plaintiffs, racial minorities and even abortion rights. Several of Judge Alito's colleagues and former law-clerks, including self-described liberal Democrats, have chimed in, saying he is not an automatic vote for one side or the other.

Former New Jersey Attorney General Robert J. Del Tufo, who as the U.S. attorney in that state was Judge Alito's superior in the late 1970s, compared Judge Alito to Justice David H. Souter, usually considered one of the high court's liberals.

"We don't want ideologues," Mr. Del Tufo said. "That's not Souter and that's not Alito."

But Alito opponents insist that, more so than Chief Justice Roberts, Judge Alito is a predictable conservative in both the political and the legal senses -- and that Democrats and Republican moderates shouldn't be afraid of opposing him on those grounds.

"As far as I can tell, Alito is an honest and honorable man.," said Villanova University law professor Gregory P. Magarian. "But I get the sense of someone who came to Washington and said, 'I want to build a conservative America, incrementally if necessary but quickly if possible.'

"Given the stakes here, what do you have to lose in opposing this nomination? The worst that can happen is that we get outflanked. But we will have crystallized a message about the stakes involved."

That both supporters and opponents of Judge Alito have made their minds up before this week's hearings conflicts with the popular notion that Supreme Court nomination is made or broken by how well the nominee performs in that setting. For example, it is widely believed that Judge Robert H. Bork, President Reagan's nominee for the court in 1987, was rejected because of his confrontational style when he testified before the Judiciary Committee.

Mr. Comiskey, who studied Supreme Court confirmations for his book, disputes that notion.

"Personality usually doesn't matter much," Mr. Comiskey said. "Bork was drowning even before he testified. He would have been defeated even if he had a more pleasant demeanor."