Federal workers who intend to blackmail the government by stopping or slowing down work until the government complies with their demands should be held accountable by the law. This planned walkout is a felony and is punishable at minimum with termination. Government employees always have the option to quit if the policies of their employer don't meet their standards.
All workers, including those employed by the federal government, should be protected from facing repercussions for their political views. In the US, dissent is a touchstone of citizens' freedoms. Unfortunately, laws related to at-will employment make these types of firings legal, so if the government and employers won't subscribe to the notion of free speech, the laws must be changed.