Sonia Sotomayor is due to replace another liberal judge
The US Senate has begun confirmation hearings later on Monday for Sonia Sotomayor, President Barack Obama's nominee to serve as a Supreme Court justice.
Kenneth Jost, adjunct professor of law at Georgetown University and author of The Supreme Court A to Z, told BBC Radio 4's PM programme what Judge Sotomayor could expect:
The Supreme Court plays a much bigger role in the US constitutional system than the Law Lords in Britain.
The justices routinely strike down laws passed by Congress or state or local legislatures; sometimes they even tell the president to get back in line. President George W Bush learned that lesson in a series of rulings against his anti-terrorism policies.
As a result, the Supreme Court confirmation process is not so much about qualifications as about politics and ideology
By any measure, Judge Sonia Sotomayor has the qualifications: degrees from two elite schools - Princeton and Yale; experience as a public prosecutor and private lawyer; 17 years on the bench first as a trial judge, and now on the federal appeals court in New York City.
In addition, if confirmed, she would be only the third woman, and first Latina, to serve on the highest court in the United States.
Republicans, however, are still upset over the way Democrats tried but failed to block President Bush's two Supreme Court appointees, including Chief Justice John G Roberts.
So Republican senators are gathering ammunition to put Ms Sotomayor on the spot when the Senate Judiciary Committee opens confirmation hearings.
She can expect to be asked about journal articles she wrote as a law student 30 years ago, and about her role more than 20 years ago in shaping a Puerto Rican advocacy group's opposition to the death penalty.
She will also face criticism for several speeches as a judge, on the role that her gender and her ethnicity have played in her decisions. In one of those speeches, she said she hoped that a wise Latina judge would often make a better decision than a white male without the same experience.
Republicans and conservative advocacy groups are calling Ms Sotomayor a "liberal judicial activist". Independent experts say her decisions stick closely to the facts and to precedent.
One expert found no overall evidence of racial or ethnic preferences in her decisions, but Ms Sotomayor was part of a three-judge ruling that upheld a city's decision to throw out results of a civil service exam because no African-Americans qualified for promotions.
Last month, the Supreme Court justices overturned that ruling, voting five to four that the firefighters had been unfairly discriminated against.
In the confirmation hearings, Ms Sotomayor will be asked about decisions she has written, on such issues as gun rights and property rights; and about issues she has not directly ruled on, like abortion and gay rights.
Her job will be to say enough to satisfy the senators but not so much as to pre-judge issues that she will have to rule on as a justice, if confirmed.
For Republicans, their job will be to be tough enough to satisfy their conservative base, without antagonising Hispanics who now comprise the largest ethnic community in the US.
In the end, however, the hearing may not matter - Democrats have the votes to confirm Ms Sotomayor, although she will not change the balance of power on the nine-member court.
She will be replacing a liberal justice - David H Souter - on a bench where five conservatives still hold sway on many of the most divisive issues.