The battle over how to project the future population of the United States has profound political implications. The question of whether America will become a majority-minority nation — and when that might happen — is intensely disputed, of enormous political import and extraordinarily complex. Two articles that appeared in the opinion section of The Times over the past few years made the case that misleading statistical artifacts used by the Census Bureau have increased the fear of a majority-minority America, a fear that played a crucial role in the 2016 election. Both Richard Alba, of CUNY, in “The Myth of...