Biden’s actually doing quite well on his left, for example. An average of recent live interview polls shows that Biden’s getting 85% among self-described liberal voters. Trump’s scoring just 9%. Four years ago, an average of pre-election polls taken after the third presidential debate put Hillary Clinton at 77% and Trump at 10% among self-described liberal registered voters.
In other words, Biden is doing better than Clinton did among self-described liberals.
Another group where Warren showed real strength in the primary season was among white college educated women. In states with entrance or exit polls, Warren got 22% of their vote on average, compared to the 13% that she got overall in those states.
Like with liberals, Biden is performing very well for a Democrat among white college educated women. An average of recent polls puts Biden at 61% and Trump at 36% among them. The final pre-election polls from four years ago had Clinton with a 52% to 36% edge.