What a changing population means for American politics

Data from the 2020 census released earlier this month shows that the United States has become significantly more diverse and more urban in the past 10 years.

The populations of people who identify as Asian or Hispanic increased sharply, and the number of people who said they belong to more than one race doubled. The white population declined in raw numbers for the first time, although it is still by far the largest racial group in the country. Those trends were even more concentrated among young people. More than half of Americans under 18...