This is pretty much my diagnosis too. The Democrats are worried about their loosening grip on “People of Color.” In order to win elections, the White upper middle class professional wing of the party needs non-Whites to vote for them as racial blocs in overwhelming numbers. If they don’t win the “Latinx,” Asian and black conservatives and moderates, they lose. This is why they are doing the systematic racism conspiracy theory now and hyperventilating about “white privilege” and “white supremacy.”
Note: David Shor has spelled out why the Democrats do this in a bunch of recent interviews. Basically, White people are intensely polarized along ideological lines, but People of Color (POC) are not even though there are similar numbers of libs, moderates and conservatives in all racial groups.