The Supreme Court decision in Givhan v. Western Line Consolidated School District, 439 U.S. 410 (1979), established the principle that public employees do not forfeit First Amendment protection simply because they communicate on matters of public concern privately to a superior.
Givhan complained about discrimination at her school and was fired
Bessie Burnham Givhan, an African American public school teacher in Mississippi, worked for a junior high school integrated in the 1970–1971 school year. She believed that the school with more black students was not receiving adequate school supplies compared to the schools with more white students. She complained about this discrimination to her principal.