Emotion is the only thing that will make a difference.
Politicians get away with enabling murder because the are separated from the consequences of the stands they take.
We need a movie, more graphic than Bowling for Columbine that tells the stories of the Sandy Hook children and their families. I would seek permission of some parents to show the photos of their slain children. Horrorific, yes, but I have lost children, and know something about the feeling. I would give permission to display their bodies if I believed it would help save others.
Include the existing news film of each House and Senate member who has dodged the issue or grandstanded for the gun merchants, every single one of them, recording their BS all posterity. If I were such an elected official, the threat alone of such a movie would move me toward reasonable gun safety positions.