[MinorityRepublican]

The one-drop rule was a legal principle of racial classification that was prominent in the 20th-century United States. It asserted that any person with even one ancestor of black ancestry ("one drop" of "black blood") is considered black.

[Albion Wilde]

The one-drop rule was a legal principle of racial classification...prominent in the 20th-century United States... that any person with even one ancestor of black ancestry ("one drop" of "black blood") is considered black.

Surely most thinking people have moved beyond that, certainly as far as the workplace; and many families practive acceptance base on commonly-held values, such as religion. You can't control whom your grown children decide to get with.