here are unwritten rules that dictate how American politics works. Former presidents shouldn’t weigh in on quotidian partisan squabbles. An incumbent senator shouldn’t support a primary challenger running against a fellow incumbent. If you’re an elected official, avoid directly comparing yourself to Abraham Lincoln—show some humility and instruct surrogates to do that on your behalf. Never try to correct a middle-schooler spelling the word “potato.” And if you want to take the pulse of white middle America, go to its de facto national capital—Macomb County, Michigan.
Every four years, as if driven by mainspring, presidents, those aspiring to be presidents and the reporters who cover them, return to the blue-collar Detroit suburbs to try out their messages and make sense of what’s happening in middle America.
