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.
No actually, they don't show that. If anything they just show he's spoiling the election for Warren. Her overall numbers nationwide and in early states have been consistently better than his for some time now. There is no sign that's going to change, especially after his heart attack. All he is doing is dragging her down with some diehards who can't let go.
That said, you can't just add all his numbers to Warren's. While I have no doubt most of them would go to her, some would go to Biden and others. But she would almost certainly take a decisive lead in IA and NH, and be much closer in SC, if he dropped out.
I mean for Christ's sake, the man is down big to two candidates in New Hampshire, his next door neighbor state that gave him 60% of the vote in 2016. If that isn't a death knell I don't know what is.