Senate Republicans have said a filibuster over Supreme Court nominee Elena Kagan is unlikely, but they have promised tough questions.

"I think we'll be looking at her testimony," Sen. Jeff Sessions, R-Ala., said. "This is going to be a big deal. It's so important how she testifies."

Democratic lawmakers are still defending Kagan's lack of experience as a judge.

The White House has now sent a letter to the National Archives urging the immediate release of papers relating to Kagan's time at the Justice Department during the Clinton administration.

"She has a lot of experience, a lot of practical experience. She's hardly a blank slate," Sen. Charles Schumer, D-N.Y., said. "You'll look at all of her writings. She wrote many articles as a professor, what she did when she was working in the Clinton White House -- that's all going to be available."

The Senate will set Kagan's confirmation hearing schedule this week.