New York City’s unionized workers are mostly minorities, for example:

https://www.nytimes.com/2013/09/04/nyregion/new-york-citys-u...

"White men account for less than one-fourth of the city’s union members, according to the study, written by Ruth Milkman, a sociology professor at the CUNY Graduate Center, and a colleague, Stephanie Luce. Fully 60 percent of all union members in the city identify themselves as either black or Latino; women who do not identify themselves as black or Latino make up an additional 17 percent of the city’s union members."