Your argument seems to be that in an work environment opinions should be kept to one's self.
Would that apply only to Republicans or to Democrats as well?
It is an utopia to pretend that the workplace should be opinion-free. Especially since the workplace on purpose tries to blur the lines between personal and professional lives: dorms on campus, cafeteria, malls and dry-cleaning amenities on campus.
If that's the direction business are going towards to then it is normal to accept that the employee comes with opinions attached.