They need to be shown that they are rapidly approaching the line in the sand.
Good work Mopar.
But which line in the sand did he establish, and which consequence (for crossing that line) did he convey? From the idiotic dem point of view, they heard that they've crossed the line where opponents of their infringing laws are willing to sound salty and give the finger before leaving the room. That doesn't establish a damn thing in terms of consequence. All a Maryland liberal thinks when they see that is, "Yeah, I guess the majority of the voters in this state and the Moms are right - these fringe gun nuts really are jerks."
That has nothing to do with reality, but that's how they think. Angry emotional outbursts convince them that what they see as their mandate to make sure Mopar's next outburst isn't an armed one is the right and proper thing. Nanny state totalitarians LOVE to have their instincts confirmed, and they just got a fine video clip for that use.