you're paraphrasing what i said, and adding things to it that i never said/intended/inferred...but, yeah...we have a first amendment here in the good old u.s. of a...and it ABSolutley gives those people the right (i.e., it's not just a privilege but a right...too many people get those terms confused) to organize and demonstrate...they have to get permits and stuff to be able to do so, but once they have them, they have the right to conduct their rally...period.
you may very well 100% disagree with it...but, that doesn't mean shit...i disagree with all sorts of stuff that i can't do anything about...another great thing about the u.s., you can disagree with all sorts of shit, in a very public manner, and no one can do shit about it...the first amendment works both ways.