Senate hearings on President George W Bush's nominee for the Supreme Court, Samuel Alito, have begun in the US.
President Bush has praised Samuel Alito's judicial experience
Mr Alito, 55, is a conservative who is likely to face questioning over his views on abortion and on the reach of presidential powers at a time of war.
However, making his opening statement, Mr Alito insisted that a good judge was one with no agenda.
If approved, he will replace Justice Sandra Day O'Connor, who said she was stepping down last year.
Mr Bush's earlier choice for the post, lawyer Harriet Miers, withdrew when conservatives refused to support her.
Mr Bush endorsed Mr Alito again on Monday, and called on the Senate to give him a fair hearing.
Judiciary Committee Chairman Arlen Specter began proceedings by pointing out that voting for a Supreme Court member was a matter of vital importance and that the committee members should not rush their decision.
He promised a "full, fair and dignified hearing", but immediately alluded to two of the most controversial issues surrounding Mr Alito's nomination.
"Judge Alito comes to this proceeding with extensive experience as a government lawyer, as a prosecutor and as a judge," he said.
"But in some of those roles, Judge Alito has expressed opinions which could now come back to haunt him, including opinions on presidential power, which suggest that he favours giving the president very extensive rights to act as he sees fit."
His views on abortion "suggest that the judge does not approve of it under almost any circumstances," he added.
However, addressing the committee Mr Alito said that good judges always "do what the law requires".
"The role of a practicing attorney is to achieve a desirable result for the client in the particular case at hand," he said.
"But a judge can't think that way. A judge can't have any agenda, a judge can't have any preferred outcome in any particular case and a judge certainly doesn't have a client."
The panel chairman said the hearing would give Mr Alito the chance to publicly declare his support for Supreme Court precedents, including the 1973 decision to legalise abortion.
The Democrats on the panel have also promised tough questions on the right to privacy and equal rights.
Democrats fear Mr Alito could swing the court too far to the right and have threatened to block his nomination, amid concerns he will use his position on the court to overturn long-standing civil rights.
The Republicans hold a 55 to 45 seat majority in the 100-seat Senate, which must approve Mr Alito.
However, the Democrats could prevent the confirmation vote by using the filibuster, a device which allows senators to block debate by talking.
Conservative Republicans and anti-abortion campaigners have welcomed his nomination.
Republican Senator Charles Grassley said Mr Alito "has a reputation for being an exceptional and honest judge devoted to the rule of law, and a man of integrity".
The second and third day of the hearings will see the nominee questioned by the committee.
The justices of the Supreme Court have immense power and are appointed until they die, resign or are impeached.