Oh please. Lincoln was kacked just after a Civil war, and it didn't rile anyone up. We as a nation were as divided as we ever will be when JFK bit it, and there was no revolution (or no more than there would have been otherwise). These sort of events have a much more unifying effect, one of their very, very few good points.
Maybe not civil war but widespread riotting caused by tensions and suspicions of "the other side" bubbling over similar to the LA riots in the 90's except nationwide. The echo chamber of social networks, websites, or other mediums could cause a sort of feedback loop until enough people snap.
Not that I'd ever expect the motorcade to include an Avenger, but how does one distinguish the random plane from the rogue plane without a TFR? They could be smaller of maybe impose a speed limit, but I understand their existence.