The road to the attorney general's office traditionally is paved with good connections. Presidents have favored their campaign managers, personal lawyers, top aides or, at least, a former senator or judge.

Now comes William Pelham Barr, bureaucrat, whose legal career began only 14 years ago with night law classes at George Washington University. President Bush's nominee for attorney general arrives at his confirmation hearings today before the Senate Judiciary Committee through the wildly unusual route of government service.

Legal observers compare Barr's nomination to President Jimmy Carter's selection of Benjamin R. Civiletti, a consummate professional who became attorney general after a similarly rapid rise through Justice Department posts. Like Civiletti, Barr is known as a cool-headed manager without political ambitions.

In 18 months as deputy attorney general, Barr was considered a conciliator at a Justice Department in turmoil during most of Attorney General Dick Thornburgh's tenure. Department officials say Barr tempered candor with discretion, a strong will with a tolerance for the personalities and views of others.

But the favorable reviews that are expected to win Barr easy confirmation are accompanied by uncertainties for some senators and former Justice Department officials. Is Barr too much an advocate for presidential power? Does his nomination mean the final ascendancy of the White House counsel over the role of attorney general? Barr owes his advancement partly to powerful White House counsel C. Boyden Gray, who controlled the administration's civil rights policy during Thornburgh's tenure.

Can Barr counter criticism that the Justice Department failed to aggressively pursue leads of criminal activity at the Bank of Credit and Commerce International? The alleged prosecutorial foot-dragging predates Barr's tenure, but the issue continues to dog the department.

That Barr, 41, is a conservative goes without question. Although some conservative groups initially questioned Thornburgh's credentials as a conservative, they have "a sense of confidence in Barr, to start off with . . . that he is one of us," said Tom Jipping of the Free Congress Foundation.

Barr told one associate jokingly: "The most radical period I had probably was when I was sort of a moderate Republican."

Barr "seems to be comfortable with" Bush's antiabortion views, according to Peter Ferrara, a friend from the firm of Shaw, Pittman, Potts & Trowbridge, where Barr handled civil cases for nine years. Barr also shares the broad interpretation of presidential powers advanced by Bush and Gray.

William Bradford Reynolds, who headed the Justice Department's civil rights division under President Ronald Reagan, said, "Bill is much more adamant and concerned about separation-of-powers issues than Thornburgh was."

"There's been a strain of strong commitment to executive power since the Reagan administration, but it's a question of how much of a good thing is too much?" said another former high-ranking Justice Department official, who spoke on the condition he not be named.

Barr has told friends his conservatism and his interest in government came early. The second of four boys born to an academic couple, Barr grew up on New York's Upper West Side. His father, an active Republican, was an assistant dean at Columbia's engineering school and later headmaster of a New York City prep school. His mother taught English to foreign students.

As a kindergartner, Barr gave a speech for Dwight D. Eisenhower. At his Roman Catholic elementary school, he announced his support for Richard M. Nixon and was taken aside by a nun, who promised to pray for him. He told his high school guidance counselor he wanted to head the Central Intelligence Agency.

Rightly figuring the CIA needed Chinese experts, Barr concentrated on Chinese studies as an undergraduate and graduate student at Columbia. He shied from college political organizations, but participated in a group that demonstrated against the seizure of administration buildings by student radicals in 1968. "I remember him as a solid, thoughtful, dependable sort of fellow," said the Rev. Vincent J. Rigdon, a former classmate.

He went from graduate school to the CIA's Chinese unit, and soon requested a transfer to legislative affairs. There he reviewed legislation and occasionally helped write testimony for the director, George Bush, while attending law school at night. "He was astute, personable, and he had a good finger on the pulse of what was going on," said George Cary, former legislative counsel for the agency.

Barr graduated second in his law school class and left the CIA for a coveted clerkship with Malcolm R. Wilkey, a judge on the D.C. Circuit Court of Appeals.

The judge proved an important connection. Wilkey, who once described Barr as the perfect blend of "intellectual brilliance and good common sense," helped Barr get a job at the Shaw, Pittman firm. He also introduced him to Mike Uhlmann, who asked Barr to work on the Reagan administration's transition team and, later, at the Reagan White House's office of policy development.

Barr's two years at the White House produced no legislation on his main issue of tuition tax credits for low-income parents of private school students. But he returned to Shaw, Pittman with another important friend: Gray, who then worked for Vice President Bush.

Barr left the law firm again to become an early supporter of Bush's presidential campaign, telling friends he admired Bush's leadership at the CIA. He helped screen vice presidential candidates and answer the deluge of questions about Dan Quayle's past, later aiding Gray in guiding Bush's presidential appointees through ethics questions.

A choice position in the administration came through in early 1989, when Thornburgh, encouraged by Uhlmann, asked Barr to head the Justice Department's Office of Legal Counsel. The OLC attracts little public attention but requires close contact with the White House counsel's office.

Barr's confirmation hearings provided a hint of his later advocacy for the powers of the executive branch. Barr testified that he "entertained doubts" about whether the post-Watergate independent counsel statute violated the Constitution by impinging on the president's power. But he said he accepted the Supreme Court's ruling upholding the statute.

As OLC chief, he provided legal reasoning used by the administration to justify the invasion of Panama and the arrest of Manuel Antonio Noriega. He also wrote an opinion that states the administration has the power to arrest terrorists overseas, even in violation of international law.

After he became deputy attorney general in May 1990, Barr advised Bush that he had the legal authority to wage war against Iraq without obtaining Congress's consent. At the same time, however, he encouraged the president to seek a congressional resolution of support, saying it would put Bush in a stronger position, according to "The Commanders," a book by Washington Post assistant managing editor Bob Woodward.

On other issues, administration officials say Barr employed a kind of quiet determination and practical approach to his advantage. After initially embracing an OLC opinion that appeared to narrow the scope of the inspector generals' powers, for example, Barr negotiated an agreement that reassured the IGs of their authority without abandoning the principle outlined in the opinion.

When Thornburgh tapped Barr as his deputy, Barr helped to bridge a painful gap between the aloof attorney general and a frustrated staff. His steady handling of a hostage crisis at an Alabama prison after Thornburgh resigned in August also helped him catch Bush's attention.

One senior Justice Department official sees the difference between Thornburgh and Barr at lunchtime. Under Thornburgh, "we would have an unwritten agenda, the attorney general's agenda, at occasional lunches. It was much more formal, hierarchical and structured," he said. "Bill has opened up the luncheons."

"Unless this guy is a superb actor and fooling everybody, he's a refreshing change," said another high-ranking Justice Department official.