On Laura Ingraham tonight, one of the panelists (I think Dana Perrino) said that Obama ran as a centrist in 2008 and 2012 as a moderate, although widely perceived as a radical outside the Democrat base.

And now, less than 4 years after leaving office in Jan 2017, Obama is perceived by Democrats as too centrist, and the positions that got Obama elected would now disqualify him from being onstage with the 25 crazies in the current 2020 primary.

Delaney and Tulsi Gabbard were the two closest to sanity in the last round of debates. And they still support open borders and de-criminalizing illegal border crossings.
It's like Rome in 380 A.D., just before the Vandals and Visigoths flood in to pillage the Empire.

I have to admit, it is very satisfying to watch Democrats who for years have slandered Republicans unfairly as racists, misogynists and Nazis and so forth, now turn those same invectives on each other in a primary campaign.
It was inevitable that steadily utilizing tactics this vicious on Republicans, at some point they couldn't resist unleashing the same venom on their own.