It says something about the anxious psychology of the Democratic Party that the endorsement of the person you used to work for is considered such a big deal. Especially given all the other candidates have dropped out of the race.

“Barack — this endorsement means the world to Jill and me,” Joe Biden tweeted shortly after Barack Obama posted a video backing his former vice president for the job he once held.

“We’re going to build on the progress we made together, and there’s no one I’d rather have standing by my side.”