WASHINGTON -- Barack Obama's election as president probably does not herald a new liberal era at the Supreme Court, since none of the conservative justices -- who are in the majority -- is expected to retire in the next four years.

But if liberals cannot take control, Mr. Obama's win has them pushing for a strong voice for social justice on the court.

"I think Obama would want to make a statement with his Supreme Court justices. We hope for a justice who can replace the lost voice of an Earl Warren or Thurgood Marshall or William Brennan," said Nan Aron, president of the Alliance for Justice, a coalition of public-interest and civil-rights groups. "It's critically important to have an Obama justice who can be a counterpoint to [Chief Justice John G.] Roberts and [Justice Samuel A.] Alito," she said.

And many expect the voice to be that of a woman.

"I think it's a virtual certainty Obama would appoint a woman. It's absurd that the Supreme Court has only one woman, and everyone recognizes it," said Thomas Goldstein, a Washington lawyer who practices before the court.

Three of the frequently mentioned candidates are Judges Diane Wood, 58, of the U.S. appeals court in Chicago; Sonia Sotomayor, 54, of the U.S. appeals court in New York; and Elena Kagan, 48, dean of the Harvard Law School. Judge Wood knows Mr. Obama from her time teaching at the University of Chicago. Judge Sotomayor could be the first Hispanic named to the court. Judge Kagan, who served as a domestic-policy adviser to President Bill Clinton, has won high marks from conservatives for bringing some intellectual diversity to the liberal-dominated law faculty in Cambridge.

It is not clear that a President Obama hopes to put the kind of person on the court that Ms. Aron and other liberals are dreaming of.

In an interview with the Detroit Free Press editorial board in October, he described Justices Earl Warren, James Brennan and Thurgood Marshall as "heroes of mine. But that doesn't mean that I think their judicial philosophy is appropriate for today."

He credited the Warren Court with ending segregation and opening doors for blacks. "The court had to step in and break down that logjam. I'm not sure you need that. In fact, I would be troubled if you had the same kind of activism in circumstances today," he said.

Since Richard Nixon's election in 1968, Republican presidents have named 12 of 14 justices to the court. Yet the court itself has never become solidly conservative -- although a victory by John McCain might have provided an opening to secure a majority on the right by replacing the older liberal Justices John Paul Stevens, 88, and Ruth Bader Ginsburg, 75.

Clinton named the only two Democrats to the court since the 1960s, and he steered away from strong liberals and instead chose veteran appeals-court judges with moderate-to-liberal records. Justice Ginsburg, soft-spoken and measured, is a champion of women's rights. Justice Stephen G. Breyer is a pragmatic problem-solver. Neither has been in a position to shape the court's work.

By contrast, Justices Warren, Marshall and Brennan were leaders of the court in its liberal era. They pressed for civil-rights for minorities and women and strengthened rights for criminal defendants. Justices Brennan and Marshall led the court in halting the death penalty for a time in the early 1970s and in striking down laws banning abortion.

The Republican appointees of Presidents Nixon, Ronald Reagan and George H.W. Bush put a halt to the liberal activism of the Brennan and Marshall era. Because of Mr. Obama's background, he is unlikely to rely heavily on advisers to select candidates for the court.

"The lawyer who will have the most influence on court appointments in the Obama administration will be Barack Obama," said Walter Dellinger, a Washington lawyer who represented the Clinton administration before the Supreme Court. "He was a highly regarded professor of constitutional law at Chicago, which has one of the most intellectually intense law faculties in this country."

A Harvard law graduate, Mr. Obama taught for eight years at Chicago and led classes on voting rights and equal protection of the law. In the Detroit interview, he praised Justices Breyer and David H. Souter, a Republican appointee, as "very sensible judges. They take a look at the facts and they try to figure out: How does the Constitution apply to these facts? They believe in fidelity to the text of the Constitution, but they also think you have to look at what is going on around you and not just ignore real life.

"That's the kind of justice that I'm looking for," he said. "Somebody who respects the law, doesn't think that they should be making the law, but also has a sense of what's happening in the real world and recognizes that one of the roles of the court is to protect people who don't have a voice." He added the "special role" of the court is to protect "the vulnerable, the minority, the outcast, the person with the unpopular idea."

If there is a second most important influence on these appointments, it may well be the vice president. Sen. Joseph R. Biden Jr. chaired the Judiciary Committee during the contentious fights over Supreme Court nominees Robert Bork in 1987 and Clarence Thomas in 1991.