She was mentioned as a potential candidate to replace Supreme Court Justice David Souter when he retired in 2009 .
Throughout her career , Karlan has been an advocate before the U.S. Supreme Court .
Karlan was mentioned as a potential candidate to replace U.S. Supreme Court   Justice David Souter when he retired in 2009 .
Throughout her career , Karlan has been an advocate before the U.S. Supreme Court .