Although CNN and Fox News have alluded to the possibility, MSNBC is the only network to report that Rudy Giuliani will endorse Sen. John McCain tomorrow in California. As McCain ended his speech at 9:59pmET, Keith Olbermann announced that NBC News learned of the endorsement, set to come at the Reagan Presidential Library, the site of tomorrow’s CNN GOP debate.

> Update: 10:17pmET- FNC is reporting that the AP has said Giuliani will endorse McCain.

> Update, update: 10:22pmET- John King reports the Giuliani endorsement on CNN.