The facts are that 25% of sanders supporters helped to elect trump by either voting for trump, voting for a third party candidate like Stein (who like sanders was supported by Russia) or stayed home
This is based on the Cooperative Congressional Election survey
https://www.npr.org/2017/08/24/545812242/1-in-10-sanders-primary-voters-ended-up-supporting-trump-survey-finds?utm_campaign=storyshare&utm_source=twitter.com&utm_medium=social
That is according to the data from the Cooperative Congressional Election Study a massive election survey of around 50,000 people. (For perspective, a run-of-the-mill survey measuring Trump's job approval right now has a sample of 800 to 1,500.)
It appears that the sanders supporters who voted for trump where (I) not really Democrats, (ii) did not like President Obama and (iiii) were racists
Party seems to have had something to do with it Sanders-Trump voters were much less likely than Sanders-Clinton or Sanders-third party voters to have been Democrats. Likewise, approval of President Barack Obama appears to be related Sanders-Trump voters approved of Obama much less than other Sanders primary voters.
And then there is race. Nearly half of Sanders-Trump voters disagree with the idea that "white people have advantages."
This tracks with broader observations about election 2016 for example, as I wrote last week, in general, the larger a state's general-election Trump vote, the less likely its residents are to perceive a lot of discrimination in the world, according to data from the Public Religion Research Institute. And another postelection study co-authored by Schaffner found a "relatively strong indication that racism and sexism were more important in 2016 than they had been in previous elections."
These are voters that the Democratic Party should not be courting or counting on. There is nothing that Biden or the party is going to do to win over these voters. Appeasing these voters will only alienate the base of the party such as voters who are proud to be Democrats, who approve of President Obama and who are not racists.
I do not feel like appeasing these voters. The only thing that will make these voters happy is the party making sanders the nominee over the objections of 70% of the party