Not sure what you are saying. It is the first amendment that grants the right to fire people you don't agree with. So presumably not everyone agrees on what free speech is.
https://en.wikipedia.org/wiki/First_Amendment_to_the_United_...
https://en.wikipedia.org/wiki/First_Amendment_to_the_United_...
The fact many supporters of this guy's firing are treating these principles as technicalities is troubling. The first amendment is a starting point, not a loophole.