I said "decades" because it wasn't until, say, the 1930s-1940s that the Supreme Court started to take the concept of free speech seriously.
The idea that the Govt cannot censor speech based on its content is the entire purpose of the right to free speech.
There are *literally* hundreds of federal court cases that say just that with plaintiffs ranging from Jevohah's Witnesses to the NAACP to anti-abortion demonstrators.
Sorry you didn't get the memo.
I got the memos. The ones that says abortion protestors aren't allowed within a certain distance of abortion clinics. The ones that says you can't shut down streets. The ones that say you don't have to be heard. Sorry the court cases agree with me across the board. And they always will because the First Ammendment DOES NOT garauntee you time, place or audience and it never will. People have just as much right to not listen as you have a right to yell your head off.