Macomb County, Michigan, a northern suburb of Detroit, is where the term “Reagan Democrats” originated. But it hadn’t voted for a Republican for president since Reagan. Obama won the county with 51 percent of the vote in 2012. Trump won it with 54 percent in 2016, a swing of nearly 50,000 votes. In several visits to Macomb, Trump depicted its residents as victims of international trade. Macomb also has significant black and foreign-born populations and is a top destination of Middle Eastern refugees, including many who voted for Trump.