So, the president can call for military action against American citizens, inside the borders of the United States, in direct contravention of US law (the Posse Comitatus Act), and that's okay? Because you're making it sound like that's totally okay, and I think that adds up to a
tiny bit more than "someone posted something we did not like".
edit: 'oarabbus_ is right, as far as I can tell, about the Insurrection Act. Even if they weren't, I suppose it'd be foolish to imagine that the US presidency in 2020 is restrained by mere legislation, save to the extent to which it permits itself to be.