Sen. Arlen Specter, D-Pa., is warning that Supreme Court Justice John Paul Stevens' retirement this year could lead to a Republican filibuster. Stevens announced he may retire as soon as this summer.
Specter says a filibuster would tie up the Senate over a Supreme Court nominee.
"I think the gridlock in the Senate might well produce a filibuster, which would tie up the Senate about a Supreme Court nominee," Specter said on Fox News Sunday.
He also told Fox News he hopes Obama would pick someone who would be check on executive power, as he says Stevens has provided.
Justice Stevens turns 90 in May. He is the oldest member of the current court and the second oldest justice in U.S. history.
The Obama administration is reportedly considering three candidates to succeed Stevens, including U.S. solicitor General Elena Kagan, as well as federal judges Diane Wood and Merrick Garland.