Do federal laws protect employees from being fired for protesting?
There is no federal law that explicitly bars employers from firing their employees for protesting.
The vast majority of American workers are at-will, meaning they can be fired for almost any reason. Exceptions include discrimination due to an employee's "race, color, religion, sex, or national origin," as stipulated by the Civil Rights Act.
The First Amendment only prevents the federal government from interfering with free speech. It does not prevent private companies and employers from restricting political speech.
In the absence of federal legislation, several states have enacted laws protecting employees from being fired for lawful "political activities." These include California, Louisiana, Missouri, Nebraska, New York, North Dakota, Oregon and Wyoming.