WASHINGTON — Republicans said Thursday that they intend to have a white firefighter whose reverse-discrimination claim was rejected by Supreme Court nominee Sonia Sotomayor testify against her in Senate hearings that open Monday.

GOP plans to showcase firefighter Frank Ricci of New Haven, Conn., indicate that Sotomayor's critics will make racial bias a central theme of the hearings.

He challenged the city's decision to scrap the results of a promotion test because too few minorities scored high enough to qualify. Sotomayor was part of a federal appeals-court panel that rejected Ricci's challenge. The Supreme Court reversed that ruling last week.

Republicans point to Sotomayor's decision as evidence she might let her personal and political views — particularly a belief in racial preferences for minorities — influence her decisions. President Barack Obama's first nominee to the high court would be the first Hispanic justice — and third female justice ever.

Democrats, seeking to counter that charge, will portray Sotomayor as a mainstream judge with fans across the ideological spectrum. Among their 15 witnesses are people who know her best.

One is the Manhattan district attorney, Robert Morgenthau, her first boss after law school. Several come with GOP credentials: New York City Mayor Michael Bloomberg, who ran as a Republican but became an independent in 2007; Louis Freeh, the former FBI director who earlier was named to the federal bench by President George H.W. Bush; and Michael J. Garcia, a former U.S. attorney in Manhattan who was appointed by President George W. Bush.

"Judge Sotomayor's developed a record as a moderate judge who agrees with her more conservative colleagues far more frequently than she disagrees with them," New York Sen. Kirsten Gillibrand said at a Capitol Hill news conference where Democratic women trumpeted their backing for Sotomayor.

Liberals expected to testify on Sotomayor's behalf include Wade Henderson, head of the Leadership Conference on Civil Rights; Theodore Shaw, former president of the NAACP Legal Defense Fund Inc.; and Democratic Reps. Jose Serrano and Nydia Velazquez, New Yorkers of Puerto Rican descent.

Sotomayor was on Capitol Hill on Thursday for the first time in weeks, meeting with newly sworn-in Sen. Al Franken, D-Minn., the most junior member of the Judiciary Committee. She appeared cheerful as she chatted with him before their private talk, telling reporters her broken ankle was much better.

Behind the scenes, she is cramming for hearings that will last about five days, including at least two days of intense question-and-answer rounds with senators.