Here's another way to look at it.
Iowa
Warren/Sanders: 43
Biden: 22
New Hampshire
Warren/Sanders: 49
Biden: 24
South Carolina
Biden: 43
Warren/Sanders: 34
Biden seems to be helped in Iowa by high % for Buttigieg and some others. There's no way Biden wins Iowa with over 30%, and there's a pretty large chance of nobody getting over 30% there. But these polls still show one main thing: Sanders is still a major contender in this race.
And Biden's firewall of Super Tuesday doesn't seem to be holding up. If he's losing all the states combined he's very likely losing all non-south states.
Should we not add Harris's vote share to the Biden bloc. What is left of Harris's support I suspect will go Biden either tactically or just directly if and when she drops out.
As far as I can tell, most of Harris’s former supporters fled to Warren, not Biden. I’m not sure why the rest of them would go to Biden.