Last Week Tonight with John Oliver: Primaries and Caucuses (HBO)

It has never been explained better to me, than in this video by John Oliver. Unfortunately, just a couple weeks ago I had proudly sent my friend a text in which I bragged about mailing in my Washington primary voter card...little did I know that the caucuses had already decided "for me" who my state would support...so I wasted a very valuable first class stamp, for naught!