Sonia Sotomayor might find it was easier to disarm Republican senators who have one eye on Hispanic voters than to sway Supreme Court justices who have lifetime appointments.

She would be the new kid on the block in a group that values seniority and relationships built over years, even decades.

But Sotomayor's self-assured performance before the Senate Judiciary Committee suggests that her very presence in the high court's private conferences could change the conversation, in the same way though perhaps not as much as Thurgood Marshall, the first black justice, did 42 years ago.

Four days of Senate hearings put the 55-year-old federal judge on the verge of becoming the first Hispanic and the third female justice. The Senate is expected to vote on her confirmation in early August.

Sotomayor displayed an easy way with her questioners.

She joked with conservative Sen. Tom Coburn, R-Okla., in an exchange about gun rights and told a story about her mother's disbelief when Sotomayor left a high-paying private practice to become a federal judge.

She told senators she was a "really good litigator" who has been successful in persuading colleagues wherever she has worked.

"I am mightily impressed," Coburn told her as he wrapped up his questioning Thursday.

To the court Sotomayor would bring life experiences in many ways totally unlike those of the other justices, even though nearly all, including her, are products of Ivy League colleges or law schools.

She grew up in public housing in the South Bronx, the daughter of working-class Puerto Rican parents who made their way to New York during World War II.

But unlike Justice Clarence Thomas, a product of the segregated South, and Marshall before him, Sotomayor never felt the sting of legalized discrimination.

Like her would-be colleagues, Sotomayor served as a federal appeals court judge. But she would be the only justice with experience as a trial judge and one of two -- Justice Samuel Alito is the other -- who was a prosecutor.

These practical differences could matter as much as her life story, and not in a predictable ideological way, said Washington lawyer and court watcher Thomas Goldstein.

"As a successful Hispanic woman coming out of Yale she could have done absolutely anything and she went and became a prosecutor," Goldstein said. "It's not the story of someone who is a liberal trailblazer."

There is little doubt among conservatives and liberals that Sotomayor's votes on the Supreme Court would look a lot like those of retired Justice David Souter, the man whose seat she would take.

But her influence within the court by virtue of her defining experiences is much harder to gauge.

The other women who have served on the court, Justice Ruth Bader Ginsburg and retired Justice Sandra Day O'Connor, have described the importance of having another woman on the court: It gives the public a better picture of the institution and makes it harder to ignore a woman's voice in internal deliberations.

Ginsburg recently said it was common several decades ago for a roomful of men to "tune out" when a lone woman spoke. There is less of it now, "but it still exists," she said in an interview with The New York Times.

O'Connor has spoken of the profound influence of Marshall, who had been a justice for 14 years when O'Connor became the court's first female justice in 1981.

"At oral arguments and conference meetings, in opinions and dissents, Justice Marshall imparted not only his legal acumen but also his life experiences, constantly pushing and prodding us to respond not only to the persuasiveness of legal argument but also to the power of moral truth," O'Connor said in a tribute to Marshall.

But O'Connor and Marshall often were on different sides of civil right cases during their overlapping years on the court. Only later in O'Connor's career did her votes seem to reflect the influence she described. She wrote a majority opinion in 2003 that upheld affirmative action policies at the University of Michigan's law school.

Sen. Arlen Specter, D-Pa., encouraged Sotomayor to "battle out the ideas that you believe in." Those fights often play out in the justices' majority opinions and dissents.

But it might take years to find out whether Sotomayor would be an effective negotiator and conciliator who can draw a wavering justice to her side.

On the current court, firmly divided between conservatives and liberals on so many cultural issues, Justice Anthony Kennedy is the only one whose vote could be described as up for grabs.

"Might she persuade Kennedy to come out differently than what Souter could persuade him to do?" Erwin Chemerinsky, dean of the new law school at the University of California at Irvine, said before the hearings. "Can Sotomayor by virtue of her life experiences move Kennedy to join the more liberal bloc more often?"

Chemerinsky said at week's end, "There's really no way to know at this stage."

John McGinnis, a Northwestern University law professor, agreed that it is hard to predict. But he thinks Sotomayor was chosen because her heritage and gender are "useful politically" to President Obama. McGinnis said Obama passed over other candidates who might have been more influential.

With the exception of a new chief, justices rarely display much influence beyond their vote in their early years. Several justices have quoted the old saw about how for the first five years a new justice wonders how he or she got there, then spends the rest of the time wondering the same thing about the others.