He stops and then puts his hands behind his back.
They put cuffs on him and he walks out with the protesters at the same time
This screen grab shows a powerful left hook right to the protester's face
He stomps on him
He places his hands behind his back and quietly goes up the step in cuffs....
It's all caught on video here.
The opening punch to the face starts at the 24 second mark
Listen to the crowd's reaction
Here's video from behind-
Dude gets rocked by this black guy
Went to the Trump rally just to see how crazy it would be........this is insane pic.twitter.com/QFwSwmNoI0— Alex Satterly (@alex_satterly) March 19, 2016