We hear it all the time, you can't be punk if you're a conservative, you can't be punk if you're communist, you can be punk if you are anything I disagree with and normally they will give some reason like "punk is about freedom and expression" completley missing the irony of the statement they are using to explain how your politics and lifestyle must match their given stereotype. But that isnt really the point of me writing this short essay, my warning is making anything in your little niche forbidden, espeically one like punk or alternative. By forbidding a certain subgroup of people from dressing like you, acting like you, or liking what you like, essentially you are making them taboo in the genre and thus making them more punk, you are making them more rebellious by isolating them from the very genre, you are making them too punk for punk, which makes them by punk's standards, cooler and more underground than punk itself.
Im not here to argue for or agaisnt what should or should not be punk because Im not really big into punk, and honestly the genre today is pretty shit mostly being the same pushing 50 bands now with corporate sponsors and whiny fags who only sing about how they hate Trump or whatever, the genre really isnt much of substance to me post maybe 2013 or so. But if you like that kind of stuff and you are of a simillar political leaning to me I would warn agaisnt being uber hostile to punks of a conservative lean, you risk giving them more credibility in doing so.