But it still pisses me off the city allowed those pricks to even gather in the first place.
First Amendment basically means the government can’t bar people from rallying or protesting based on what beliefs they are doing so in the name of. Same reason why there are no hate speech laws, and why basically the only expression that is inherently criminal is expression that requires doing another crime to create (think child pornography, as you can’t make it without sexually abusing children).