They all leveraged their experiences in the White House for plum gigs in the media-communications business.,Then there’s Karine Jean-Pierre, who also worked for Biden. On Wednesday, she announced that she was leaving the Democratic Party to become an independent with the launch of a book called Independent.

In a coming book, Ms. Jean-Pierre will describe a “betrayal” by her party when Joseph R. Biden Jr. ended his re-election campaign. Democrats were quick to criticize her.