In the comments section on this question, someone took offense at calling african-americans black (because not all blacks are african). Then took offense at using the term african-american (because the question was about black people, but specifically pertaining to Americans), so they suggested that "black American" be used as an all-inclusive term to describe people with dark skin in America.
As a white American, this immediately set off alarm bells in my head. The term "black American" sounds like the kind of thing I would never think of uttering in public. (I can picture the dagger glares already. I can hear the angry follow up responses. White progressives are mean).
Is "black American" an acceptable term to refer to all black people in America, even those who are not ethnically African?
Could it be that it sounds like dog whistle and that is why I instinctively am against it?