Wait for it...
I actually have a theory to explain this.
He's not being genuine with all this tearing down Ted Cruz signs. That's not really him. He's trying to virtue signal or something.
And his outward actions posing as a Democrat or progressive or whatever are so disintegrated with his actual conscience, that his subconscious knowledge of how fake and ridiculous he was being (by his own subconscious evaluation, I'm saying) overwhelmed him and took possession of him, and in the moment he goes nuts, it's his subconscious steering him for a minute and actually viciously parodying his conscious behavior.
If that is what is happening here, this is an amazing phenomenon to see so clearly and captured on video like this.
Imagine being so disintegrated. It's incredibly uncomfortable to be so turned against yourself, and I can imagine how embarrassed he must have been to find this video of his likeness having such a terrible meltdown going nationally viral on social media.
I laugh because it is funny, but I don't laugh too hard, because it could happen to any one of us.