Want to handicap John Roberts'chances of being confirmed as the next chief justice of the United States? Keep your eyes on U.S. Sen. Dianne Feinstein.

California's Feinstein will be in a pivotal position when the Senate Judiciary Committee begins confirmation hearings for Roberts. Every nominee for a federal judgeship whom she has opposed since her election in 1992 has been rejected. Every nominee who had her support has been confirmed.

Before the death of Chief Justice William Rehnquist, while Roberts was still President Bush's nominee to succeed retiring Justice Sandra Day O'Connor, Feinstein had articulated a set of standards that will determine her vote. Those standards will serve her and her colleagues well as they consider whether Roberts should be the nation's top judge. Here they are:

First, senators must have access to Roberts' writings in order to make an informed decision.

This is important because much of Roberts' record remains cloaked in secrecy. For one thing, he does not have a lengthy record as a judge. But more than that, the Bush administration refuses to hand over documents from Roberts' work in the Office of the Solicitor General from 1989 to 1993. Roberts served then as a high-level political appointee, not a civil service government lawyer, and wrote 81 Supreme Court briefs.

Senators have asked the White House for documents from 16 of those cases. Previous administrations have provided such documents when they nominated political appointees to the bench. Roberts is capable of telling senators where his writings reflect his own thinking and where he is playing devil's advocate.

Sen. Arlen Specter, R-Pa., the committee's chairman, wrote in a 2000 book that senators should "resist, if not refuse to confirm, Supreme Court nominees who refuse to answer questions on fundamental issues."

Over the weekend, Specter seemed to be sticking to that precedent. Feinstein should press him to do so. She should insist that failure to produce the documents is grounds for a "no" vote.

Feinstein and her colleagues next should focus on a pattern of court decisions in the last 10 years limiting the ability of Congress to act on many national issues.

In 1995, the Supreme Court for the first time in 60 years struck down a law based on a narrow reading of the Commerce Clause in the Constitution. That clause is the legal foundation for the full range of national laws in our interconnected economy and society, from civil rights to the environment to public health and safety. Since 1995, the court, often on narrow 5-4 votes, has struck down part or all of such laws as the Gun-Free School Zones Act, Violence Against Women Act, the Brady Handgun Violence Protection Act and the Age Discrimination in Employment Act.

Clearly, some justices would like to use a restricted view of the Commerce Clause to limit Congress' ability to act on national issues. It is fair, then, to ask what views Roberts, who as chief justice would have the power to mold opinion among the justices, holds on that constitutional provision.

One indication of Roberts' view is in a dissenting opinion in a case about a housing development, where seven other judges rejected his narrow reading of congressional power. In his dissent, Roberts wrote about congressional regulation of a "hapless toad that, for reasons of its own, lives its entire life in California."

Senators should ask whether Roberts would extend this dissenting logic to laws protecting lakes or rivers within a state, impacting the ability of Congress to pass such laws as the Clean Water Act and Safe Drinking Water Act. He needs to be pressed on this.

Finally, Feinstein and her colleagues will want to examine in great detail Roberts' views about privacy.

Feinstein has made it clear that the fundamental right to privacy includes freedom from governmental intrusion into intimate decisions such as whether to bear a child or end a pregnancy: "It would be very difficult for me to vote to confirm someone to the Supreme Court whom I knew would overturn Roe v. Wade, and return our country to the days of the 1950s."

While the seminal Roe v. Wade decision does indeed rest on the notion of a right to privacy, the importance of such a right extends far beyond the politics of abortion. Justice Louis D. Brandeis in 1890 called it the "right to be let alone."

Roberts has referred to a "so-called right to privacy"; on this matter, too, he needs to be pressed.

Even though she sits in the Democratic minority, Feinstein will have a crucial role in these hearings. In this nomination process, she will be a bellwether to whom the nation can look to see what Democrats stand for and what set of principles they'll take into the 2006 election. It is a heavy responsibility. Fortunately, she seems to be up to the task.