Supreme Court nominee Sonia Sotomayor addressed her critics directly on Monday, telling senators at her confirmation hearing that "fidelity to the law" and "rigorous commitment" to the Constitution guide her judicial philosophy -- not her ethnicity, gender or empathy.

The federal appellate judge pledged to serve the "larger interest of impartial justice" before a packed gallery of senators at a nationally televised confirmation hearing. 

"In the past month, many senators have asked me about my judicial philosophy. It is simple: fidelity to the law," said Sotomayor. "The task of a judge is not to make the law -- it is to apply the law. And it is clear, I believe, that my record in two courts reflects my rigorous commitment to interpreting the Constitution according to its terms, interpreting statutes according to their terms and Congress's intent, and hewing faithfully to precedents established by the Supreme Court and by my circuit court. 

"In each case I have heard, I have applied the law to the facts at hand," she said. 

But that conclusion was up for debate as the 19 members of the Senate Judiciary Committee stuck to clear party lines in their opening statements at the hearing. 

Sotomayor is expected to face questioning from senators on Tuesday, but the committee's leading Republican, Sen. Jeff Sessions, set the tone for the GOP side, pointing directly at statements made by Sotomayor during her judicial career that he called "troubled" and prejudiced. 

"Do I want a judge that allows his or her social, political or religious views to change the outcome? Or do I want a judge that impartially applies the law to the facts, and fairly rules on the merits, without bias or prejudice?'" Sessions, of Alabama, said. 

"Our nominee has made some troubled rulings," he added, citing Sotomayor's ruling in a reverse discrimination case that was overturned last month by the U.S. Supreme Court in a 5-4 ruling.  Sessions also cited Sotomayor's much-publicized remarks about the notion that a "wise Latina" woman might be better suited than a white male without the same life experiences.

Sessions' charges were echoed later by Republican Sen. Orrin Hatch, who also criticized President Obama for saying that personal empathy is an essential ingredient in judicial decisions. 

"Today we are urged to ignore Judge Sotomayor's speeches altogether and focus only on her judicial decisions. I do not believe we should do that," Hatch said. 

But committee Chairman Patrick Leahy and others lauded Sotomayor's journey to Capitol Hill Monday, calling the would-be first Hispanic justice "a truly American story." 

"Hers is a success story in which all Americans can take pride," Leahy said, adding that Sotomayor has a "deep respect for judicial precedent" and "commitment to justice." 

Sotomayor was introduced to the senators with lengthy and congratulatory introductions from New York Sens. Chuck Schumer and Kirsten Gillibrand, who both praised the judge as a "extraordinary legal mind" whose commitment to the Constitution is "unyielding."  

The two praised the New York-born and Ivy League-educated veteran of 17 years on the federal bench, calling her the most experienced nominee to the U.S. Supreme Court in 100 years. 

Democratic Sen. Russ Feingold defended Sotomayor against claims from her critics that she will be biased in her rulings because of her racial and ethnic heritage.

"This charge is not based on anything in her judicial record because there is absolutely nothing in the hundreds of opinions she has written to support it," Feingold said.  "That long record -- which is obviously the most relevant evidence we have to evaluate her -- demonstrates a cautious and careful approach to judging. Instead, a few lines from a 2001 speech, taken out of context, have prompted some to charge that she is a racist."

"Judge Sotomayor puts rule of law above everything else," echoed Sen. Charles Schumer, D-N.Y.  Schumer said Sotomayor's judicial record shows she is "mainstream," adding that she has ruled in agreement with Republicans "95 percent of the time."

In his first major statement since being sworn in as the junior senator from Minnesota last week, Sen. Al Franken called the judge "an outstanding jurist" and "exceptional individual" whose inspirational story is one which "all Americans should take great pride in."

"I may not be a lawyer, but neither are the overwhelming majority of Americans. Yet all of us, regardless of our backgrounds and professions, have a huge stake in who sits on the Supreme Court, and we are profoundly affected by its decisions," he said. 

Sen. Lindsey Graham, R-S.C., though critical of some of Sotomayor's past statements and rulings, told the judge he expects her to be confirmed "unless you have a complete meltdown."  

"And I don't think you will" have a meltdown, he added quickly.

Though moving relatively smoothly, anti-abortion protesters several times disrupted the hearing's opening statements. The first came from a man in the back of the room, who interrupted Sen. Dianne Feinstein's remarks by shouting: "Senator. What about the unborn?"

Also arrested was Norma McCorvey, a.k.a. Roe in the 1973 landmark Roe v. Wade abortion case. McCorvey, 61, has since become an anti-abortion activist.

In the nearly seven weeks since Obama nominated Sotomayor to replace retiring Justice David Souter, critics have labored without much success to exploit weaknesses in her record.

The most fertile ground for Republican questioning appears to be on race and ethnicity, focused on Sotomayor's "wise Latina" comment and the white firefighters from New Haven, Conn., who won their Supreme Court case last month.

In a speech in 2001, Sotomayor said she hoped a "wise Latina" often would reach better conclusions than a white male without the same life experience.

By a 5-4 vote last month, the high court agreed with the firefighters, who claimed they were denied promotions on account of their race after New Haven officials threw out test results because too few minorities did well. The court reversed a decision by Sotomayor and two other federal appeals court judges.

Republicans have signaled they may also press the 55-year-old New Yorker to explain past rulings on gun rights and her position on abortion.

Schumer predicted that Sotomayor will win significant Republican support and get more than the 78 votes, including 22 Democrats, that John Roberts received in his confirmation as chief justice in 2005. The Senate has 58 Democrats, 40 Republicans and two independents who generally side with the Democrats.

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The Associated Press contributed to this report.