No, dissenting speech is not protected in both cases.
Freedom of speech has to take place in the proper forum to be granted. For example, there is no freedom of speech on private property. If the owners of the property or their representatives don’t approve of what you are saying, then you can and will be ejected from that property.
Even on public property, you usually need some kind of permit to legally protest. And if dissenters show up, then usually the permit-holders have the legal right to ask them to leave. After all, its their rally, they organized and paid for it, let the dissenters hold their own.
And finally, the speech has to be orderly. You are legally entitled to whatever opinion you want to have. However, as the saying goes, your right to swing your fist ends where my nose begins. Just because you have an opinion, no matter how important you think it is, does not mean that you can break a law. Free speech does not even trump municiple ordinances when it comes to behavior. Blocking traffic, harrassing pedestrians, and destroying property are not excused because you have a message.
Personal experience in all of these cases is a Police Officer, Security Guard, whatever, will come over and ask or demand that the dissenter stop. The dissenter, who invariably flunked 8th grade Civics, will then exclaim louded that its a free country blah blah blah. Then he’s facing trespassing charges. Which causes him to get more indignant and start yelling, escalating the charges to disorderly conduct. Then the arrest is attempted, and he refuses to go, adding resisting arrest without violence. Then assault, battery, resisting with violence and finally, after pepperspray and being hogtied, he is dumped into the back of a police car, still bitterly professing that he is be oppressed.
Americans sure love their Freedom of Speech, too bad so few actually understand it…