The insanity rune is the polling that has Kamala as more radical than like Bernie Sanders in the mind of the voters. This is simply because Kamala is a liberal black woman from California while Bernie is an old white guy
Squid
Also, a sad secondary effect is that for many moderate literally just means "the candidate is a white man".
It's been studied extensively and its part of why so many black electeds poll to the right of their constituencies especially the larger they get. Obama was a huge exception obviously.