Even as Republicans grow hopeful about at least keeping the Senate during the midterm elections, one part of America looks sure to be brutal for their party: the Rust Belt. Democrats this November could conquer this region that was central to Donald Trump’s shocking win in 2016. The prospect of another pendulum swing back to blue illuminates what Mr. Trump’s election in 2016 really meant.

Rust Belt voters in the last election and in this one were and are declaring a deep dissatisfaction that persists even in good economic times, because it is grounded in something cultural and deeply local: the collapse of community.

Democrats are polling way ahead in this year’s governor’s races in Pennsylvania and Michigan, and they have very good chances of taking over the governor’s mansions in Ohio and Wisconsin. These, famously, were the four Rust Belt states Mr. Trump swung from Democrat in 2012 to Republican in 2016 and that carried him to the White House.

The picture is similar in Rust Belt Senate races: Democrats will easily win Ohio, Pennsylvania and Michigan, and they will probably win Wisconsin.