Obama,meanwhile, has picked up the endorsement of another former Bush administration official. Days after former Secretary of State Colin Powell gave his backing, former White House Press Secretary Scott McClellan told CNN’s D.L. Hughley he’ll also be voting for Obama.

Scott McClellan: “From the very beginning, I’ve said I’m going to support the candidate that has the best chance of changing the way Washington works and getting things done. I will be voting for Barack Obama.”

Earlier this year, McClellan broke ranks and criticized the White House over the war in Iraq, the handling of Hurricane Katrina, and the leak of CIA operative Valerie Plame’s identity. Obama received another Republican endorsement Thursday from CC Goldwater, the granddaughter of former Republican senator and presidential candidate Barry Goldwater.