The Boston Tea Party was not a riot. No one burned down their own neighborhood. No one looted local merchants. It was a kinetic protest to be sure, and it was "violent" to that extent. But violence and rioting and looting are all different things.
Riots are self-destructive. Today the aggrieved burn down the grocery store. Tomorrow, they complain no one will sell them food. Was their anger justified? Sure. Was shooting themselves in the breadbasket an effective response? Not really,
America's past nastiness will excuse some of its present stupidity, but it will not make it smart. Rioting is stupid; it is what stupid people do. Donald Trump is President because stupid people voted stupidly. They had plenty of reason to want to try "something new" in response to our feckless government, but they were still stupid as Hell to try what they tried. Rioting is like that: a self-destructive tantrum, always justified, never defensible.