The problem is not James, it's just that if Trump is losing MI by eight points like this poll is forecasting there is no way that this seat could flip.
You’re right that there’s no way this seat flips if Biden wins MI by this much, but I do think James could outperform Trump by 2 points or so with a better campaign (but certainly not with the kind of lazy campaign he’s been running—he’s barely been visible).
The problem for James is that Peters, unlike Stabenow, has gone negative against him early and hard. Democratic super PACs have hammered James relentlessly for saying that Obamacare is an abomination that needs to be repealed.
Yeah, and James has been pretty much absent from the campaign trail, unlike Peters. Some people have compared this race to FL-SEN 2018, and so far it looks like they were (unintentionally) right: Nelson is James, Scott is Peters. 
It would be hard, Trump is actually a pretty good kind of republican for MI (not too religious + protectionist), it's easy to see some Trump/Peters voters in place like Macomb or Saginaw county but Biden/James voters are much harder to imagine (maybe some in Grosse Pointe or Bloomfield Hills) because the vast majority of people who will vote for Biden, at least in MI, are simply not open to vote for a conservative, downballot republican candidate who would solidify the conservative grip on the US Senate, that's why Peters is pretty okay.
