As I argued yesterday, observers are underestimating the key role of declining white noncollege margins for Trump. Perhaps that has something to do with the fact that, even with vast improvements, Biden still tends to run a deficit with these voters.
But that's not the right way to look at it. Cutting your deficit in one group can be just as important that increasing your advantage in another group--in fact more important, depending on the size of the group and the magnitude of the change.
Case in point: new Fox News polls have Biden ahead in Michigan and Pennsylvania by, respectively, 9 and 11 points. What's the most important driver here? White noncollege voters. In each case, this group should be roughly half of voters in 2020. The Fox polls have Biden's current white noncollege performance in both states at -10. But that compares (using States of Change data) with -29 for Clinton in PA in 2016 and -21 in MI. These huge swings move the vote heavily in the Democratic direction even if Biden is still losing the group overall to Trump in both states.
You cannot understand what's going on in this election without taking this dynamic into account.