The part at the end of the video (from about 35:11) is particularly powerful.  To quote Rachel Maddow:
"We are a country that actually does have pseudo fascists and violent racists, black shirts and brown shirts, on the very far fringes of right-wing American politics.  We do have persistent skin heads, and neo-nazis and klansmen.
That persistent fringe variety of American monster, though, has never before been attached to and attracted to, a front-running major party presidential campaign the way they are to Donald Trump.  For the first time since I have been alive, we are legitimately watching to see if the Black Shirts and Brown Shirts officially attach themselves to his campaign in some way."