CNN is reporting that Tom Ridge will announce this afternoon that he is stepping down as Secretary of Homeland Security. Potential successors rumored:

• Joe Allbaugh, director of the Federal Emergency Management Agency.
• Asa Hutchinson, undersecretary for border and transportation security, and former Republican member of Congress.
• James S. Gilmore III, former Virginia governor.
• Bernard Kerik, interim Minister of the Interior for Iraq and former New York City police commissioner.
• Mike Leavitt, Environmental Protection Agency Administrator.
• Mitt Romney, the governor of Massachusetts.
• Frances Townsend, White House adviser on homeland security.

Update: It's Kerik.