If you've been paying any attention at all to journalism in recent years — maybe not a good idea, but if you have — you surely have noticed those stories predicting, often with a certain relish, that the United States is about to become a majority-minority country. Such predictions, as the Obama administration Census Bureau director noted in 2014, "made demographic change look like a zero-sum game that white Americans were losing." Such fears contributed to Donald Trump's election in 2016. No one wants to vote for the side that seems to be saying, "Hurry up and die." But are...