"I come before the committee with no agenda. I have no platform," he told the panel on the first day of confirmation hearings, which are expected to go through the end of the week.
The senators, in their opening statements, laid out their varying opinions on the way the hearings should be conducted as well as their views on the role of the Supreme Court, previewing potential points of contention.
In his statement, Roberts cited the need for humility and impartiality on the part of the judiciary as well as a need to respect the supremacy of law.
"A certain humility should characterize the judicial role," he said. "Judges are like umpires, they don't make the rules they apply them. ... Nobody ever went to a ballgame to see an umpire."
Committee Chairman Arlen Specter, R-Pa., promised an open atmosphere for the remaining days of the hearings, stating that senators had the right to ask any question they see fit and the nominee has the right to decide how to answer.
But other Republicans said some case-specific questions are inappropriate and urged their Democratic colleagues to not ask them and Roberts not to answer them.
Sen. Orrin Hatch, R-Utah, said judicial nominees should "draw the line" and refuse to answer certain questions. Hatch said some inquiries might compromise a judge's ability to rule impartially, which they commit themselves to do by an oath.
"Judges take that oath, not senators," Hatch said.
Sen. John Kyl, R-Ariz., said questions on political issues are improper. "The seat on the Supreme Court is not a political let alone a legislative office," he said.
Democrats countered that the lifetime appointment of Supreme Court justices requires a thorough hearing because citizens have one opportunity, through their elected representatives, to scrutinize a nominee.
Sen. Herb Kohl, D-Wis., said that an appointment to the Supreme Court carries an "awesome power and responsibility" and that senators only "have a few days to ask questions on behalf of the people."
Some Democratic senators have expressed dissatisfaction with the Bush administration for not releasing certain documents from Roberts' career as a government lawyer at the White House and the Justice Department, when he wrote multiple memos advising his superiors on a wide range of legal and political issues.
Sen. Charles Schumer, D-N.Y., said that senators on the committee had only seen the "tip of the iceberg" when it came to Roberts and that the nominee's "ideology matters."
Republican senators decried what they said has been deterioration of the nomination and confirmation process in recent decades, calling the current process too rancorous and overly political.
"Our confirmation process is not a pretty sight," said Sen. Jeff Sessions, R-Ala. He said left-leaning political interest groups would oppose any nominee made by President Bush.
Though they approached the issue from different angles, nearly all the senators on the committee expressed dissatisfaction with the way the Supreme Court and the federal judiciary has operated in recent decades. Democrats generally decried what they called a rolling back of "progress" on individual and minority rights as the result of recent Supreme Court decisions. Republicans largely said "judicial activism" was rampant in the judiciary, leading to court decisions based on judges' opinions rather than the law and the will of the people.
"The two parties have different criteria on how they are going to judge [the nominee]," NewsHour political analyst David Brooks said Monday. "When you listen to the Democrats talk about the job of judging, and what criteria one should use, they talk about values, they paint the judiciary ... as almost a third branch in the march of progress toward making a better country ... not very different from a political branch. Then when you hear Republicans describe the judiciary, there is a chasm between the political branches of government and the judicial branches. So they see it as two very different jobs, and therefore they have two very different views of how to judge."
Sen. Joseph Biden, D-Del., said the country is currently embroiled in an "ongoing intellectual debate on the meaning of the constitution and the power of the federal government." Biden, quoting former Chief Justice John Marshall, said he believed the "Constitution should be adapted to the various crises of human affairs."
"We need a more modest court, a court that is not a super-legislature," countered Sen. Sam Brownback, R-Kan., "one that looks at the Constitution as it is, not what we wish it were." Brownback said in the 1973 Roe. v. Wade ruling, the high court "invented a constitutional right to an abortion" where none had existed before.
Sen. Diane Feinstein, D-Calif., disagreed, hailing the Roe v. Wade decision as a matter of recognizing a fundamental right to privacy inherent in the Constitution and said she felt a special responsibility as the lone woman on the committee to protect "hard earned autonomy" of American women.
Roberts joined many senators in paying tribute to former Chief Justice William Rehnquist, who died Sept. 3 after 33 years of service on the court. Roberts, who was initially nominated to replace Justice Sandra Day O'Connor, was then tapped by President Bush to fill the chief justice's role.
-- Compiled from wire reports and other media sources