Sadly, though the US may be growing more "brown" in appearance, it is not going to become numerically brown. Many people who are identifiably brown, but "white-adjacent," are now being courted by conservative white groups who dangle before them the perk of being considered white. Unfortunately, if, and when, given a choice between being considered a "person of color" or "white," they choose white.

Cubans, some of whom are quite brown, have always considered themselves "white," and I've met a few South Asians, quite dark, who also consider themselves "light" or "white."

If you can't beat 'em, then get them to join YOU.