WASHINGTON – With his spotless conservative credentials, many say former Solicitor-General Theodore Olson has the experience and intellect to make him a possible nominee to the Supreme Court should a vacancy open up in President Bush’s second term.

Mr. Bush has relied on Mr. Olson to defend many of the administration’s key policies before the top court, from religious school vouchers to presidential powers in the war on terrorism, and he shares the judicial philosophy the president says he admires.

Mr. Olson won the vast majority of cases he argued before the Supreme Court and was commended for his “wise and invaluable counsel” to the administration by the outgoing attorney general, John Ashcroft.

“If the president were to appoint him, he would be of the stature to go right to the chief’s position,” said the executive director of the Committee for Justice, a conservative group that advocates for the president’s judicial appointments, Sean Rushton.

But Mr. Olson’s hard-edged partisan past and the expansive interpretation of executive powers he has urged before the court promise to make him one of the potentially most divisive candidates.

His age, 64, may also be of concern to those who want to see an enduring conservative hold on the court.

When he was confirmed by the Senate to the post of solicitor-general, all nine Democrats on the Senate Judiciary Committee voted against his nomination.

Senate Democrats are unlikely to overlook the fact that Mr. Olson represented Mr. Bush in litigation before the Supreme Court in Bush v. Gore. The court’s ruling in the case ended a recount of votes in the state of Florida and paved the way for Mr. Bush to assume the presidency.

Mr. Olson also aided the Paula Jones sexual harassment suit against President Clinton, and he represented Clinton accuser David Hale during Senate hearings investigating the Clintons’ role in the Arkansas land deal.

Democrats are also likely to object to Mr. Olson’s vigorous arguments on behalf of the administration in recent cases involving detainees in the war on terror.

Mr. Olson’s wife, Barbara, perished in the attacks of September 11, 2001, aboard a plane that crashed into the Pentagon.

Mr. Olson later lobbied for robust antiterror laws, saying it is what his wife would have wanted him to do.

But his legal arguments in favor of broad executive powers in the war on terrorism prompted Justice O’Connor to make the pointed comment in a written opinion that, “A state of war is not a blank check for the President.”

“Putting him in charge of the Supreme Court would be putting in a fox as one of the guards in charge of the henhouse,” said Kenneth Hurwitz, a lawyer with Human Rights First, a group that has filed friend-of-the-court briefs against the administration in the detention cases.

Many issues relating to the cases, from the legal status of the American detention camp in Guantanamo Bay, Cuba, to interrogation policies and command responsibility for abuses of prisoners, are likely to return before the court in coming years, and Mr. Olson could face a conflict of interest in hearing them, Mr. Hurwitz said.

The general counsel for the liberal group People for the American Way, Eliot Mincberg, said Mr. Olson’s appointment would be “particularly dangerous as we see an administration that is willing to assert a broad executive power.”

But his role in making the case for a muscular chief executive would not be a black mark with the public, Mr. Rushton predicted.

“Democrats have to be careful about running too many people up the flagpole because they are so darn tough on terrorists. Eventually, they are going to realize that is not the best politics for them,” he said.

As solicitor-general, Mr. Olson prevailed in the majority of his 26 arguments before the Supreme Court, on issues from protecting children from online obscenity to overturning affirmative-action admission policies at the University of Texas Law School.

Before becoming solicitor-general, Mr. Olson unsuccessfully defended the right of the all-male Virginia Military Institute to exclude women students despite receiving state funding. The court also rejected his defense of a Colorado initiative that would have barred cities and towns from passing gay rights statutes.

A native of Chicago, he was educated in California public schools and earned his bachelor’s degree from the University of the Pacific in Stockton, Calif. He received a law degree from the University of California at Berkeley. In the early 1980s, he served as a lawyer in the Reagan administration.

In an interview on CNN after the election, Mr. Olson joked that his name was being floated as a potential nominee only “to scare small children.” He said he is perfectly happy in the private sector – he is now a lawyer with the firm Gibson, Dunn & Crutcher – and he has not pondered a hypothetical court appointment.

Asked whether he would overturn Roe v. Wade were he on the court, he declined to answer, explaining that such a case would have to be judged “in its context.”