There is NO undifferentiated right to “protest”.
People CLEARLY have the right to speak, but NO right to compel or force attention from uninterested private citizens. So, since “demonstrations” DO compel attention, they are not “free speech” per se.
They are not the free exercise of religion, they are not exercising freedom of the press - which leaves peaceable assembly and petition as possible sources for a “right to protest”.
I have always read assembly and petition together - that is, peaceable assembly FOR THE PURPOSE of petition for redress of grievances cannot be made illegal (by Congress).
I was a participant in a borderline peaceable mob in November 1969 which went to Washington to present Mike Mansfield and John McCormack with petitions urging the House and Senate to end the war in Vietnam. I believed (and I believe today) this ‘assembly” was protected by the First Amendment.
But Congress had the AUTHORITY and the ABILITY to do what we wanted them to do.
In the case of “civil rights demonstrations” which openly broke the laws, the assemblies were acknowledged by the demonstrators to be illegal, their purpose was to get arrested (to shame the conscience of their opponents), they never claimed immunity under peaceable assembly and petition. The only counter example was the March on Washington 1963, which explicitly was for the purpose of presenting Congress, the Senate specifically, with a petition to release from filibuster and to pass the Civil Rights Act.
People in our day have gotten very confused about this. They have conflated the moral purpose of the illegal civil rights demonstrations with the few large assemblies (demonstrations) to petition Congress or State Legislatures for redress of grievances to make any loud and unruly assembly, bearing no petition and asking no element of the government for redress under their legitimate authority, legal under the peaceable assembly and petition clause.
Marches for the purpose of “protest” are not legal, they are not protected by the First Amendment, WHETHER OR NOT they are “peaceable”. If your issue is that you object to (and want to stop) the inauguration and exercise of office of the legally elected President, to whom is your petition directed? What arm of the government can “Fuck Trump”? What arm of the government can “blow up the White House”?
Peaceable assembly and presenting petitions, even if the assembly is large, is protected. Insurrectionary mobs are not protected, and may be dispersed or prevented from assembling in the first place, by any means necessary.
“I believed (and I believe today) this ‘assembly” was protected by the First Amendment.”
Be that as it may, it was grotesquely misguided, and everyone there shares in every subsequent atrocity committed by the Vietnamese communists.
As General VoNguyen Giap wrote, “What we still don’t understand is why you Americans stopped the bombing of Hanoi. You had us on the ropes. If you had pressed us a little harder, just for another day or two, we were ready to surrender. It was the same at the battle of Tet. You defeated us. We knew it, and we thought you knew it. But we were elated to notice your media was helping us. They were causing more disruption in America than we could in the battlefields. We were ready to surrender. You had won.”
The war was won, but our media and the anti-American left snatched victory from our hands and passed it back to the forces of Evil.