https://electoral-vote.com/
It's more than that, and I think we've discussed this before. EV.com had another piece on this today analyzing a Quinnepiac poll. When looking at how the top 5 are doing with demographics, these are the categories that they over perform with:
Biden: (1) black people; (2) moderates; (3) seniors
Warren: (1) strong liberals; (2) white college graduates; (3) baby boomers
Sanders: (1) young people; (2) strong liberals; (3) poor men, esp. 35-49
Harris: (1) somewhat liberal people; (2) the rich; (3) white college graduates
Buttigieg: (1) Age 18-34; (2) somewhat liberal people; (3) white college graduates
Biden and Sanders poll better with lower income men, and Warren with women, which is why Biden is more often the 2nd choice for Sanders voters over Warren. Kind of interesting that the category that Harris and Buttigieg poll well with is the affluent.