jackk > in the over 240 years of this country we have had a peaceful transition between presidents except for one.
Not sure whether we/you actually was here for 240 years. Otherwise, you might know that not everything was perfect: there were transitions resulting from assassinations, one transition lead to Civil War, Aaron Burr almost became President, White House was burned, a Soviet agent was a VP …
You may constructed in your mind that this event is somehow unique in features you describe – but in what sense it is more concerning than several Presidents who were killed? Killing of an Austrian prince caused WW1, but not in US. And so a demonstration that walked into an under-protected Congress was not a burning of Reichstag.