Is there another explanation? Remember how the progressive stance used to be that dissent was patriotic? Why not now?
Dissent is now known as racism. It has to be that way because any opposition to this president must be shown to be illegitimate.
Remember the wonderful behavior of the progressive Occupy Wall Street crowd? Contrast that with the extreme actions of the "violent fringe" Tea Party.
You know, actually getting the proper permits, cleaning up after themselves, not defecating everywhere or committing rape.