I don't know what he's comparing black and Hispanic support to, and I'm not sure about the House races, but it is true that Biden lost traditional bellwether counties and states. The answer to that is simple:Can you provide links for these claims, rather than just expecting us to not only accept them blindly, but also to discuss them in the proper context?
The point about losing OH ,Iowa and FL is meaningless, since the EV in all of those states is already figured in and no one is dispelling that Trump won those states...Biden lost some minority support, but he did far better with whites than HRC did in 2016.
From a Pew analysis just posted in June...
Biden got 92% of
In 2020, Biden improved upon Clinton’s vote share with suburban voters: 45% supported Clinton in 2016 vs. 54% for Biden in 2020. This shift was also seen among White voters: Trump narrowly won White suburban voters by 4 points in 2020 (51%-47%); he carried this group by 16 points in 2016 (54%-38%).
Bi
Bellwether is something a district gets after the fact. It means that a particular area has been predictive of results in the past. It doesn't mean there is anything inherent about that area that should lead anyone to think it will continue to be predictive in the future. Bellwethers change. A few decades ago, it was really, really important who won Ohio. Ohio doesn't mean as much now. Virginia and Nevada are much more telling.
Basically, states/counties/districts/etc. that have a partisan makeup that falls roughly along the same area as the potential tipping-point state in the EC are going to be bellwethers. As demographics change, so will those bellwethers.