John Roberts’ confirmation as the 17th chief justice of the United States is a significant achievement for the Bush administration, a political science professor said Thursday.”John Roberts was an ideal choice for Bush,” political science professor Donald Jackson said. “The president wants to leave a lasting impact on the Supreme Court and nominating a young chief justice is a great way to do that. He could serve for twenty years or more.”

Roberts’ appointment will not affect the balance of the court because he is replacing fellow conservative William Rehnquist, who Roberts clerked for, Jackson said.

Another member of the political science department, Chairman Jim Riddlesperger said, Roberts is the kind of appointment presidents make when they want an easy confirmation but it’s a trade-off for the president because justices have a way of migrating once they’re appointed.

Bush appointed Roberts, but this does not necessarily mean Roberts will always vote the way Bush wants him to, Riddlesperger said.

Jackson added that Roberts is a mainstream conservative and is as strong as anyone on economic conservatism but it was hard to tell, from the conformation hearings, if he is socially conservative.

Bush originally named Roberts to succeed retiring Justice Sandra Day O’Connor in July. Rehnquist’s death led to the second nomination on Sept. 6, and Roberts now will be confirmed as chief justice, while O’Connor remains on the court until the president selects a new replacement – an announcement expected soon.

“Those opposed to the Roberts nomination were going through the motions,” Jackson said.

It would have been hard to stop Roberts’ confirmation since the Republicans have the majority but the Democrats will put up more of a fight if O’Connor’s replacement is a hard-core social conservative, Jackson said.

O’Connor, the first female justice, had an independent streak in her voting record so her replacement could have a swing affect on the court, especially regarding women’s reproductive rights, Jackson said.

Political science professor Ralph Carter said, “There will be a lot of pressure on Bush to nominate a female, a Hispanic or both to replace O’Connor.”

The Associated Press contributed to this article.