Funny no one wants to answer these questions. But the truth is (and I know this cause Employment law is my shit!) Employers will only tolerate the most neutral of speech. They don’t want employees going off on either side of the political spectrum because it causes them all sorts of problems, like the ones you have identified.
So while at work, people need to present as blank, cookie-cutter automatons who love and die for their company and nothing else.
If they happen to get caught being something else, God forbid it happens at work. They will probably be out of there. If it happens outside of work and gets back to work, yeah there will be problems and the employee could be done.
I cant believe people are acting like they don’t know how extraordinarily restrictive employment relationships are.