Former Sen. Sam Nunn, the pre-eminent Democratic voice on national security and national defense, just endorsed Sen. Barack Obama (D-Ill.).
Former Sen. David Boren and former Labor Secretary Robert Reich did as well.
The Nunn endorsement is a very, very, very big deal. Not only does it give Obama national security backing, but Nunn is enormously respected by superdelegates.
Expect more announcements soon.