Everything to do with the confederacy, except from teaching about the civil war, should be banned in the US. That flag they love, ban it. Statues, rip them down. Locations named after conspirators, rename them. The civil war was an attempt to destroy the US and divide it in two. They lost, fortunately. All associations to the traitors they were should not be allowed. People who claim “it’s my heritage” heritage of what exactly? That you’re white? Your skin says that. That your family was racist? Not a good quality to be flaunting and something you should probably come to terms with.
I think the better action, over a blatant violation of the 1st amendment, would to push back ourselves instead of trying to get the government to break its own rules.
Anytime someone uses the phrase "War of Northern Aggression", pointedly correct them in saying "(American) Civil War". Anytime they spout "states rights", amend them with "to own humans and demand other countries return the people they want to enslave". Rock the damned boat and use the 1st amendment how it should be. They are not protected from other people having disdain for them for being stupidly proud of atrocities. And you know what, being proud of being descended from racist slave owners is not a protected class. Just saying.
The government shouldn't suppress speech. But we can certainly give them consequences for being assholes.