It would seem the left is consumed with the act of "insurrection." Perhaps because historically, it has been their choice when they do not get what they demand in governing the American people.
It is why we had the war between the states. It is why we have had riots recently in many of our Democratically controlled cities.
If Trump wins in November, the Democrats need to accept that it is the people's choice. This despite their persistent attempts to override the will of the people. So, it doesn't surprise me at all that a top Democrat has threatened such action, if they don't win in November.