That's "as a result of improvements in the design of the race and ethnicity questions, processing and coding", not some massive influx, or "invasion".
These data are all published, visualized, and extensively explained on the US census website.
E.g.;
https://www.census.gov/library/stories/2021/08/improved-race-ethnicity-measures-reveal-united-states-population-much-more-multiracial.html
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