Deep in the bowels of the nation's 2020 Census lurks a quiet milestone: For the first time in modern American history, most white people live in mixed-race neighborhoods. This marks a tectonic shift from just a generation ago. Back in 1990, 78% of white people lived in predominantly white neighborhoods, where at least 4 of every 5 people were also white. In the 2020 Census, that's plunged to 44%.