Warren Professor of American Legal History Morton J. Horwitz said the change of Roberts’ nomination from associate to chief justice would not make the confirmation more difficult.

“At the symbolic level the chief justice represents the Supreme Court on ceremonial occasion,” Horwitz said. “So the chief justice has a larger potential public voice. But if I were a senator it would not fundamentally change my vote if he were nominated to be an associate justice or chief justice.”

Despite a lofty title, the chief justice holds a single vote on the Court. He does, however, possess several additional powers, both practical and ceremonial, the most important of which is the ability to choose which justice will write an opinion when the chief votes with the majority. This is particularly important because the chief justice can shape precedent by joining with the majority, when he might have voted otherwise.

“There is also a sense among the Justices that the chief justice is at least first among equals and deserves a special hearing when trying to forge a consensus on divisive issues,” Fallon wrote in an e-mail. “Not every chief justice succeeds in putting a personal stamp on the Court, but the chief justice has a better chance of doing so than any of the other Justices.”

The chief justice also has a variety of duties outside the Supreme Court. He selects judges to serve on various judicial committees, including the Foreign Intelligence Surveillance Court, often called the “wiretap court.” Beyond that, the chief justice holds a variety of other duties, including presiding at impeachment hearings, swearing in the President, and chairing the Judicial Conference of the United States, the top administrative body of the federal court system.

Horwitz said that, although the chief’s additional powers are important, they are not as great as they first seem.

“We measure time in terms of presidencies and chief justiceships,” he said. “This exaggerates the role of the chief justice in history. For instance, the Rehnquist court had a lot of aspects who were not just Chief Justice Rehnquist.”

Last week, as the president announced the re-nomination from the Oval Office with the nominee at his side, Bush praised Roberts and Rehnquist, for whom Roberts clerked after finishing law school.

“It’s fitting that a great chief justice be followed in office by a person who shared his deep reverence for the Constitution, his profound respect for the Supreme Court, and his complete devotion to the cause of justice,” Bush said.

“I am honored and humbled by the confidence that the President has shown in me,” Roberts said as he accepted the nomination. “I’m very much aware that if I am confirmed, I would succeed a man I deeply respect and admire, a man who has been very kind to me for 25 years.”

If Roberts is confirmed, he will be, at age 50, the youngest chief justice since John Adams, Class of 1755, nominated John Marshall, then just 45 years old, in 1801. Roberts also has relatively little experience on the bench, having served as an appeals court judge for just three years and written only 47 opinions. But Horwitz said that what is so unique, historically, about the Roberts nomination is his lack of prior political activity.

“Most Supreme Courts were not populated by people who spent a lot of time on the judiciary,” he said. “They were mostly political appointments. Most chiefs have come from off the court rather than on the court. In the past, the Chief Justice was often a fairly substantial politician like Governor Earl Warren or John Marshall, who was Secretary of State. Someone with so little political or judicial standing has rarely been appointed to the chief justiceship.”

Roberts has experienced a meteoric rise to the top since he arrived at Harvard in the fall of 1973. He graduated summa cum laude in History in just three years and went on to graduate magna cum laude from HLS while serving as the Managing Editor of The Harvard Law Review.

He went on to clerk for Circuit Judge Henry Friendly and Rehnquist, when Rehnquist was an associate justice on the Supreme Court. Roberts also worked in the Justice Department, serving as Deputy Solicitor General—one of the government’s main lawyers before the Supreme Court—and later had a private practice. By the time President Bush appointed him to the D.C. Court of Appeals in 2002, Roberts had argued 39 cases before the Supreme Court and was known as one of the finest appellate litigators in the land.

Since he was tapped for O’Connor’s seat in July, Roberts has managed to weather the grueling scrutiny typical of a Supreme Court nomination. Thousands of documents have been released from government archives, and Roberts was given the highest rating of “well qualified” by the American Bar Association. Although several liberal interest groups voiced their opposition, no senators have come out against him.