"Nonetheless, many states do have laws that forbid employers from restricting some employee speech and political activity. And according to a 2012 paper by note

"Nonetheless, many states do have laws that forbid employers from restricting some employee speech and political activity. And according to a 2012 paper by noted free speech scholar Eugene Volokh, California has such a law—and it's among the nation's strongest. The paper gives examples of how "political activities or affiliations" described in the law are broadly defined, and cites an influential court ruling from 1979: “[P]olitical activities,” the California Supreme Court has stated, “cannot be narrowly confined to partisan activity,” but instead cover any activities involving the “espousal of a candidate or a cause,” including participating in broad social movements such as the gay rights movement." http://fortune.com/2017/08/08/google-memo-legal/ http://fortune.com/2017/08/08/google-memo-legal/ California's protections are his best chance. Link to Volokh paper: http://www2.law.ucla.edu/volokh/empspeech.pdf http://www2.law.ucla.edu/volokh/empspeech.pdf