Forgive me if this triggers awful memories, but on election night last November, as we watched the returns come in showing Donald Trump winning Pennsylvania, Michigan and Wisconsin, something just didn’t feel right. In most polling and punditry circles, there had been literally zero chatter about Trump potentially sweeping these three states — a feat that no Republican candidate had accomplished since Ronald Reagan in 1984. How had such an unlikely thing happened? After the election, we heard a wide array of theories, including the ones about how previous Obama voters in the Rust Belt didn’t believe the Hillary Clinton campaign and the Democratic Party spoke to their economic grievances, so they flipped to Trump — a whiplash-inducing switchover given the chasmic differences between number 44 and 45. There may be some threads of validity to that analysis, but was it enough of a messaging oversight by Team Hillary to flip states that hadn’t gone red in more than three decades? ...