So, what comes with his endorsement?
More than I thought, as it turns out.
Steve Clemons at his blog
Ted Kennedy has the largest machine in the Democratic Party. When I used to work in the Senate, I marveled at the Kennedy franchise -- at the number of people who had started with Kennedy, who then went on to different positions in government and the private sector, and then came back for his annual "friends only" Holiday Party at which he and his wife always showed up in some extremely cool but outrageous attire (I was there for Beauty and the Kennedy Beast). There were thousands upon thousands at this close friends' party.
But there is no doubt that Kennedy's endorsement is not about Massachusetts nor about an aging white liberal -- it is about the thousands and thousands of followers who owe their careers to Ted Kennedy.
So, Teddy has an army of liberals ready to roll out. I did not know this.
Obama is fresh enough and new enough that he doesn't have such a machine; now Kennedy has gifted Obama an enormous vehicle which Kennedy hopes Obama will take as his own and keep intact.
And, he doesn't want to see the giant crew that he built fall apart after he's gone. He's looking to hand it off I guess.