When President Trump won Michigan in 2016, the first Republican to do so since 1988, he swung 12 counties from blue to red, outperformed Mitt Romney in nearly every county, and outperformed Romney by 25 percentage points in 14 counties.

You could count those 14 counties with the largest swings to Trump as the populist places. Guess what? Those were among Joe Biden’s best counties in Tuesday’s primary. Biden outperformed his statewide average in 13 of those 14 counties, including all 11 of the counties where the Romney-to-Trump swing was greater than 25%.