U.S. President Barack Obama has asked the Senate to move quickly to approve his historic pick for the Supreme Court, but the partisan debate over his choice is already under way.

Tuesday, President Obama nominated federal appeals judge Sonia Sotomayor, the daughter of Puerto Rican parents, to replace retiring Justice David Souter.

Rival party members on the Senate Judiciary Committee, which will hold confirmation hearings on Sotomayor, disagreed about the nominee during a televised interview on the NBC network Wednesday.

Republican Jeff Sessions said Sotomayor must explain a 2005 videotaped remark in which she says "court of appeals is where policy is made."  Sessions described the remark as "very troubling" and said judges should rule based on the law and not their personal or political beliefs.

Democrat Charles Schumer defended Sotomayor, noting she immediately followed the controversial remark by saying she does not advocate courts making law.  He described her as a jurist with an "outstanding" record.

Democrats hold a strong majority in the Senate and, barring any unexpected problems, Sotomayor's chances of being confirmed are very good.

Sotomayor is in line to become the first Hispanic justice on the high court and one of three women to serve on it.

Mr. Obama has said he was looking for a nominee who appreciates the principles of the U.S. Constitution and also can understand and identify with ordinary people.

Justice Souter is scheduled to retire next month after serving 19 years on the Supreme Court. 

Some information for this report was provided by AP.