Show me one law in any state that makes politics one of the protected classes.
You misunderstand what a "protected class" is.
Protected classes are NOT the only ones that are supposed to be protected.
All rights are supposed to be protected, and rights are infinite, making them impossible to enumerate.
The few that ARE listed are ONLY the ones so historically often abused, that they had to be specifically enumerated.
But in no way should anyone EVER assume that only those specifically enumerate classes are the only ones protected.
So "protected classes" actually are the ones which are the most often abuses, not the only ones protected.
And it should be obvious that trying to protect only specific classes by listing them, would be totally and completely illegal.
That would be unequal treatment under the law, with listed classes being protected while those unlisted not being protected.
That would be totally illegal.
Any specific protection of an enumerated class which does not also protect all unenumerated individuals would clearly be totally illegal.
That is what judges are for.
Rights are infinite, and not limited to specific legislation.
Rights to pre-exist all legislation and are the basis for being able to pass any legislation.
Judges are to understand the abstractions and general principles of justice, so they can interpret a hierarchy of rights on the fly, in easy individual case.