The White House says there are no front-runners to replace retiring Supreme Court Justice John Paul Stevens.

But there are a few on the administration's list of possibles that are sure to spark debate from conservatives.

First, there's Diane Wood who's currently on the 7th Circuit Court of Appeals and is considered radical on the abortion issue.

There's also U.S. Solicitor General Elena Kagan who has her own abortion issues and also attacked the ROTC as being pro-homosexual. She would be considered a non-mainstream pick.

Goodwin Liu is also on the list. He was recently nominated to be on the 9th Circuit Court of Appeals and has no judicial experience but is only 39. Liu is also a Rhodes Scholar and was born to Taiwanese immigrants -- the type of life story President Obama likes.

Conservatives would likely disapprove of Liu, though, since he's very liberal, especially on issues like affirmative action and same-sex marriage.

Meanwhile, Democrats were in complaint mode Tuesday, saying Republicans are already holding up lower court nominees and don't want that to spill over to the Supreme Court pick.

The expectation is that Obama will make his pick in the next few weeks and Senate hearings will begin in the summer, before August recess.