This is absolutely permitted in America. It is illegal in countries like Germany which have no strong free speech protections.
They're Klan Acts, because a bunch of guys in masks and robes marching through is obviously a threat of violence.
As a general rule of thumb, almost every time someone brings an edge case about whether or not speech is First Amendment-privileged before SCOTUS, SCOTUS rules in favor of the speech. (The main exception is speech of students in school.) SCOTUS hasn't specifically ruled on anti-mask laws to my knowledge, but I strongly doubt it would uphold those laws.
You don’t have to pontificate. The link was right there.
If you assume a just government that doesnt demand revenge for every petty slight, you are living in a fantasy land.
I am staunch believer in the moral and societal good of free speech.
Anonymous speech is far more dubious.
Like, protests seem valuable. Protests while wearing robes and masks however...