Where am I? What am I doing here? Which one of you is Barack? Did I remember my pants?
We're all perplexed too, Joe.
I think a few things may have happened. Democrats realized that it's either you or the socialist. Obama picked up the phone and started telling people, "Listen, I can't with you people any more. Just go with Joe." There's also the likelihood everyone endorsing is already making their plans to run against Mike Pence in 2024. That is, unless Donald Trump declares himself Grand Poobah and runs for a third term. Either way, Democrats are already looking ahead.
Which is funny, when so many of them seem to forget to look behind. In 2008, Biden was only picked to be vice president because the week Obama was supposed to make his pick, Russia invaded Georgia. Otherwise, I'm fairly certain it was going to be Tim Kaine. Since two inexperienced people were no longer a good sell, Barack went with the old-timer.
Then in 2012, they benched Biden from campaigning. He wasn't even allowed to speak in prime time during the convention. Traditionally, the Vice President of the United States is the Wednesday night headliner. Biden barely had a spot on the preliminary card that Thursday. He was basically Joe Schmoe fighting on UFC Fight Pass before the big PPV.
Now, he's most likely going to be the Democrat nominee twelve years later. All this time, I thought Republicans were supposed to be the ones who fell in line.