"It was reported that comic Jackie Mason referred to President Obama as a 'schwartze' (phonetically, shvartza), angering sophisticated Jews in his audience who knew that the Yiddish term for black inserted in an otherwise all-English conversation is always meant to be derogatory, and is akin to the 'N' word. Mason insisted the word isn't demeaning." (source)

"There she was, twenty-five years old, raising three kids, slaving like a shvartsa to keep a clean house." (Weekend, by Tania Grossinger and Andrew Niederman, 1980, p. 45)