Preaching to the choir members isn't going to stop it. Didn't you learn anything from Washington? Make a TV commercial showing an actor in a police uniform at a desk with a stack of forms. The camera zooms in and the officer looks up and says, "I would rather be out on the street chasing criminals, but I have a thousand background checks to do on people who are following the law. This is why you need to vote against I-###."
Or the camera shows a group of women in a self defense class learning with the instructor telling them how many crimes have been stopped with the use of the firearm. A woman student turns around properly holding an unloaded gun and says, "I have to get a background check just to take this class and learn how to use a gun to defend myself with. Why should the police be required to spend their time and resources investigating me just so I can learn how to defend myself when they could be stopping the criminal that I might have to use this tool to defend myself against?"
Or a 19 year old girl standing at a private shooting area watching her dad shoot. She says, "Daddy, can I learn how to shoot your gun in case someone breaks into our house when you are gone and tries to rape me?" Daddy turns to the camera and says, "No, sweetie, I'm sorry, I can't teach you how to shoot my gun because you have to have a background check first before I can loan it to you."
You won't win the fight by calling gun owners.