From NBC's Domenico Montanaro
Sen. Jay Rockefeller has thrown his support behind Obama. Rockefeller is the chairman of the Senate Intelligence Committee.
SUPERDELEGATE COUNT (as of 3:40 pm ET, Feb. 29)
NOTE: Obama has picked up 38 delegates since Super Tuesday, Feb. 5. Clinton has lost a net of 6.
Super delegate numbers reflect totals gathered by the NBC News Political Unit from the campaigns and public endorsements.
The NBC News Hard Count stands at Obama leading Clinton 1,194-1,037.