When Harris had to pick a VP, all media kinda agreed it should be a white male, to balance the fact that she is black and a woman. So Walz is the DEI hire.
If you ask me, I'm upset no one picked up that this consideration was sexist and racist, although it is indeed the best choice for her to win, which reflects how bad US can't get over race and gender.
Democrats not voting for Harris is a real threat. What you're describing is called voter apathy. Historically speaking the republicans win the elections with the highest amount of voter apathy. Democrats win in situatioms where higher voter turnout exists.
Essentially speaking, the democrats biggest enemy is themselves.