This is worth a read. It would appear that the quick thinking of a sole policeman drew the angry mob away from the open senate door.
Tinfoil hat time. What if this was a coordinated attempt to take out the presidential line of succession, starting with Pence or enough of them to justify Trump declaring martial law and somehow using this justification to cling on to the reins of power, or at least contest it. What if Barr was not on board and that's the reason he exited. What if Trump tried to get the military on board as you usually need the military for a successful coup, and when that was knocked back they just went ahead with it anyway. And what if the misdirect from this cop saved the republic.
Tin hat off