I will say that I happen to agree with the relevant USSC precedents (from what little I know and have read about them.) I would also point out that your earlier post insisting that people be consistent about their support of USSC decisions is a bit of a chimera. One can be opposed to a ruling, while still admitting that it sets an important precedent (and has importance as the final interpretation of a particular law.)
If the government of D.C. (or any other jurisdiction) says you cannot bring a busload of people in to protest because the bus isn't licensed, or the driver isn't licensed, or it tries to park in an area not permitted for busses -- all such "content-free" and mechanical restrictions are entirely legitimate. They apply to every bus, regardless of the political views of the passengers, if they have any political views in common.
But, if the jurisdiction tries to bar your bus and its passengers because it has a quarrel with the subject of your protest -- what you will say and represent when you get off the bus -- THAT IS a violation of the First Amendment and will be slapped down in a New York minute by any competent court, anywhere in the US.
Do you see the difference?
Congressman Billybob