IMO if you knowingly go to a campground where you feel unsafe, a firearm can cause a problem to quickly escalate to serious levels. If you feel unsafe, don't stay, or leave at the earliest opportunity.
FWIW I've never felt unsafe at any campground, even the slightly seedy ones. We never stayed at the one that made us feel like it wasn't a smart place to stay. It may have been fine, but we just got the wrong vibes from the place.