(Bloomberg Opinion) — One of the most important trends to emerge from the 2020 Census didn't get much attention last week, but it reveals more about how both the U.S. economy and its politics will look in the coming years than most other details focused on by the news media. Americans' vision of their city of the future typically involves skyscrapers populated by large new technology companies. Yet the 2020 Census didn't point to San Francisco or New York as the fastest-growing city, or even one of the dozens of smaller metros that emulate them. The fastest growing metro area in the U.S. is the Villages, a retirement community in central Florida.