
After the havoc that I’m gonna wreak
No more words will critics have to speak
I’ve got the answers to the tangled knot
Sleep tight in your cot

would it be acceptable for the KKK members to proselytize the citizens assembled on government property, who are there to fulfill government requirements
how about the nation of islam
or possibly the new black panther party
only if you would agree those first amendment expressions on government grounds to a captive audience would be acceptable could you then also agree that the Bible thumper reading from his religious tract should also be found acceptable

If it is acceptable for one group then it should be acceptable for them all. I have encountered countless muslims preaching around towns in various spots. NBPP and other racists groups pushing their hate around towns. I cant recall any time I have ever seen the KKK to be honest but they are no different than the black panthers or naacp or any religious group including islam or catholics or OWS, pro or anti abortion groups, political groups pushing a candidate or anyone else.
Equality.

☮★☭★☭☮ Just a democratic-socialist in the heartland of America.
"Life is beautiful. Let the future generations cleanse it of all evil, oppression, and violence, and enjoy it to the full."

Because the same rules that prevent him from doing what he did would also prevent him from going on about a cause to save the whales. It isn't the content of what he was saying that he was arrested for. It was his disruptive behavior towards a group of people who had no practical means to avoid what he was saying, in a non-public forum. If he had gone over to the street corner and spoke from there, he would have been fine. If he had been talking about Scientology, environmental crusades, how much he loves American Idol, or pretty much anything that wasn't suggesting a commercial transaction, he would still have been arrested. If he had been doing this outside of a mall, where people didn't have to stop and listen to him, he would have been fine.
That's how the law works in this instance. His choice of subject matter was not relevant to his arrest.
The word "militant" is applied to religious people when they bomb buildings full of innocent people and to atheists when they speak with a non-deferential tone.