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, and speculation quickly mounted on his potential choices.

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 will face heavy pressure from advocacy groups to pick either a woman or the first Hispanic. 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 often 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 some of the more frequently mentioned 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, 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.

-- Deval Patrick, 52, governor of Massachusetts, is a friend of Obama's and 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.

-- Kathleen Sullivan, 53, director of Stanford's Constitutional Law Center, is a strong abortion rights advocate and a former dean of Stanford Law School.

-- 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.

-- 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 Alan Elsner)