Why is it offensive. What is the word for the color black in Spanish? Does the color black have a negative connotation? Or did racist cultural attitudes turn what was a neutral term in to a highly charged weapon of oppression.

I think the OPs point was “deep state” has a deliberate, highly charged, negative connotation.

Don’t conflate the horrible reality of racism with the historical origin of a racial insult. The OP is merely using it as an example to illustrate how terms acquire meaning through time and social norms. Not excuse their existence.