President George W. Bush on Monday announced John Roberts as his candidate to replace the late William Rehnquist as the Chief Justice of the United States, a move that has surprised some.

Bush originally nominated Roberts to fill the seat of Associate Justice Sandra Day O’Connor, who announced her retirement from the U.S. Supreme Court on July 1.

Because of this switch, the dynamics of the nomination have changed, said Supreme Court expert and University law professor David Stras. Roberts, a conservative, would be replacing a fellow conservative rather than O’Connor, who tends to be more of a swing voter on controversial issues, such as abortion.

“With Roberts replacing Rehnquist it won’t change much, if at all,” Stras said. “The real change will occur when O’Connor is replaced.”

Some reacted to the nomination with surprise that Bush overlooked justices already serving on the court in favor of Roberts, who has yet to be confirmed by the Senate, but Stras said it was a good decision.

“Politically, this was a smart move for him because (Justice Antonin) Scalia and (Justice Clarence) Thomas would be much harder to confirm – both have a long track record,” Stras said.

There is also plenty of historical precedent of presidents picking chief justices who haven’t served on the Supreme Court, he said. Earl Warren, who served as chief justice from 1953 to 1969, had no U.S. judiciary experience.

Roberts, on the other hand, has a long history with the court system. From 1980 to 1981, he was a law clerk to then-Associate Justice Rehnquist, the man he is slated to replace.

From 1982 to 1986, he was associate counsel to the president under President Ronald Reagan, and from 1989 to 1993, he served under President George H.W. Bush as deputy solicitor general. As such, he won 25 of the 39 cases he argued before the Supreme Court for the government.

Some University students are worried Roberts’ inexperience as a Supreme Court justice will hinder his ability to be a good leader.

Nate Meyer, an agriculture and food management junior, said he thought justices who have been on the court longer might be better suited to be chief justice. He also said he was concerned about Roberts’ age.

Since an appointment to the Supreme Court is a lifelong commitment, Roberts, at the age of 50, could potentially sit on the court for many decades, leaving a lasting impression on American policy.

“It’s like walking into a big company for the first time as its CEO,” Meyer said.

Chemistry graduate student Annie Leung had a similar view.

“I’d feel better if (Bush) picked someone who had done it before,” she said.

Regardless of his inexperience, Stras said, Roberts has a “very good” chance of being confirmed by the Senate.

“While the memos from the early ’80s will give him some trouble, I don’t think there’s enough opposition out there that will delay his nomination unless something catastrophic comes out,” Stras said.

The memos, which Roberts wrote as a young government lawyer, show him criticizing affirmative action and programs to fight gender discrimination.

Federal court expert and University law professor Allan Erbsen said he thinks Roberts would be a “fairly pragmatic administrator.”

“One interesting thing about Roberts is that he was a leading practitioner before the Supreme Court for about 15 years,” Erbsen said. “He’ll be able to hit the ground running – Roberts has a vast reservoir of practical knowledge and insight.”

Stras, who was a clerk for Justice Clarence Thomas and knew Rehnquist, said Roberts will probably mimic Rehnquist’s leadership style if he is confirmed as chief justice.

“From my experience, Roberts would be similar, but he hasn’t been on the court as long and might not command as much respect,” Stras said. “My guess would be he would try to be as similar as he can.”

Stras said he remembers Rehnquist professionally as someone who was very stern, organized and made sure that things didn’t run into overtime.

Privately, however, “he was a very funny, witty guy,” Stras said. “He was a really nice, sincere man. They are losing a charismatic leader.”