Donald Trump's presidential campaign famously promises to "Make America Great Again." As a rule, no one should think too hard about the meaning of bumper sticker political slogans. But ever since Trump rolled it out nine years ago, his slogan has quietly asked some seemingly unanswerable questions: When was America great before? And when did that greatness vanish, thus necessitating its recovery?
The answer, it turns out, isn't a year. It's an age.
