WASHINGTON — Sonia Sotomayor has decided advantages as she begins the most important trial of her long legal career, a nationally televised consideration of her nomination to be the first Hispanic and just the third woman on the Supreme Court.

Beginning today, she will tell her compelling up-from-poverty personal story to a jury tilted strongly in her favor — Democrats hold a comfortable majority on the Senate Judiciary Committee and a filibuster-resistant 60 votes in the Senate.

Still, Republicans signaled that they will press the 55-year-old New Yorker and veteran federal judge to explain past rulings involving discrimination complaints and gun rights, as well as comments that they say raise doubts about Sotomayor's ability to judge cases fairly.

The sharpest comments about her so far came Sunday from Sen. Jeff Sessions of Alabama, the senior Republican on the committee.

Sotomayor has said repeatedly in speeches over the past 10 years that personal experiences influence a judge's decisions, Sessions said.

"She has criticized the idea that a woman and a man would reach the same result. She expects them to reach different results. I think that's philosophically incompatible with the American system," Sessions said on CBS' "Face the Nation."

Her defenders have tried to paint a picture of Sotomayor as a meticulous judge, one who "goes out of her way, as a good jurist should, to follow the law, no matter what her sympathies tell her," Sen. Chuck Schumer, D-N.Y., told The Associated Press last week.

Sen. Patrick Leahy of Vermont, the committee chairman, said Sunday on CBS that Sotomayor's 17-year record on the federal bench shows her to be a "mainstream judge."

The questioning of Sotomayor won't even begin until Tuesday, after the 12 Democrats and seven Republicans on the committee — including Sen. Orrin Hatch, R-Utah — use up to 10 minutes each for preliminary remarks and the nominee makes her opening statement.

President Barack Obama chose Sotomayor in late May to take the place of Justice David Souter, who retired last month. The switch would not appreciably alter the balance of the power on the conservative-leaning court.

Obama called Sotomayor on Sunday to wish her luck at the hearings, compliment her for making courtesy calls to 89 senators and express his confidence that she would win Senate approval, the White House said.