FACTBOX: Possible Supreme Court nominees for Obama

WASHINGTON (Reuters) - President Barack Obama will make his first appointment to the U.S. Supreme Court to replace retiring Justice David Souter soon, and speculation has mounted on his potential choice.

Obama, a former constitutional law professor, is expected to choose a judge who would follow in the footsteps of the left-leaning Souter and be unlikely to dramatically change the court’s ideological balance.

But he faces heavy pressure from advocacy groups to pick a woman or the court’s first Hispanic. An early list floated by a source familiar with his thinking was dominated by women.

The last three justices named to the court were white men, and the court’s only woman, Ruth Bader Ginsburg, has been diagnosed with pancreatic cancer. Ginsburg says she does not plan to retire any time soon.

Obama said he wanted someone with a sharp and independent mind to replace Souter. He often said on the campaign trail that his ideal Supreme Court justice would be someone who could empathize with the daily lives and hardships of Americans.

Here are six names floated recently as possibilities to fill Obama’s first Supreme Court vacancy:

-- Sonia Sotomayor, 54, a judge on the 2nd U.S. Circuit Court of Appeals in New York. Sotomayor, a graduate of Yale Law, would be a hit with two political constituencies given her Hispanic heritage.

-- Elena Kagan, 49, is the solicitor general, appointed by Obama to argue cases before the Supreme Court, and a former dean of the Harvard Law School. She served as associate counsel to President Bill Clinton and as a clerk to Supreme Court Justice Thurgood Marshall, and taught at the University of Chicago Law School where Obama also taught.

-- Diane Wood, 58, a judge on the 7th U.S. Circuit Court of Appeals in Chicago, also knows Obama from teaching at the University of Chicago Law School. She has been targeted at times by conservative groups for her defense of abortion rights, creating a potentially difficult confirmation process. She served in the Justice Department’s Antitrust Division during the Clinton administration.

-- Jennifer Granholm, 50, governor of Michigan, is a Harvard Law graduate and former attorney general who is a Democratic Party star but whose popularity at home has been hammered by the state’s difficult economic conditions.

-- Janet Napolitano, 51, is homeland security secretary and the former governor of Arizona. A former state attorney general and U.S. attorney for Arizona, she is a former corporate lawyer and was on the team of lawyers who represented Anita Hill at the contentious 1991 confirmation hearings for Justice Clarence Thomas. She had accused him of sexual harassment when he was her supervisor.

-- Carlos Moreno, 60, is the only man included on the early White House list. A former Los Angeles city attorney and U.S. District Court judge, he was appointed to the California Supreme Court in 2001. He is often seen as the court’s most liberal voice, and he supported the court’s 4-3 ruling legalizing same-sex marriage.

The White House says other candidates are also under consideration. Here are some other frequently mentioned possibilities:

-- Kathleen Sullivan, 53, director of Stanford’s Constitutional Law Center, is a strong abortion rights advocate and a former dean of Stanford Law School. She would be the first openly gay justice.

-- Leah Ward Sears, 53, is chief justice of the Georgia Supreme Court and the first black woman to serve as a state chief justice in the United States.

-- Deval Patrick, 52, governor of Massachusetts, is a friend of Obama and was an assistant attorney general in the Clinton Justice Department. The second elected black governor in the United States once worked at the NAACP Legal Defense Fund, but he has had his share of political troubles at home.

-- Cass Sunstein, 54, a professor at Harvard Law School and a former teacher at the University of Chicago Law School, is a former clerk for Justice Thurgood Marshall. He has been appointed by Obama to the post of regulatory czar, overseeing all governmental regulation.

Writing by John Whitesides; Editing by Vicki Allen