Racial diversity growing in the US.

Every state and Washington, DC became more diverse to varying degrees between 2010 and 2020. There are methods for measuring diversity — the Census Bureau's uses probabilities based on racial and ethnic makeup. Specifically, the probability that two randomly chosen people in a given place belong to different racial and ethnic groups. The higher the probability, the higher that location's diversity. USAFacts used this measurement and data from the 2010 and 2020 censuses to see where the nation is becoming more — or less — diverse.

Hawaii is the most diverse state, with Asian, white, and multiracial people each representing more than 20% of its population. Maine is the least diverse: it's the only state where non-Hispanic white people are more than 90% of the population.
2020's least diverse county was Starr County on the Texas-Mexico border. With a 98% Hispanic population, there's less than a one in 20 chance that two random people in the county come from one of eight different racial or ethnic groups.
One hundred and twenty-four million people (or 37% of Americans) live in counties that are more diverse than the US overall. New York's Queens County is the largest of these diverse counties: it's home to more than 2.4 million people with no single racial or ethnic group making up more than 28% of the population.

Polluting the gene pool: