This is mine. I posted it in another thread as well.
Look at some of the stuff coming out of JPFO. They've got some good leads that should strike home pretty hard with our "enlightened" youth concerning the origins of American gun prohibitions. When you can put a photo of a hanged black man surrounded by hood wearing klansmen together with the statute that disarmed the black man prior to their midnight visit, it strikes a pretty sensitive nerve.
For better or worse, the common meme today is that WWII is ancient history, and the world could never go down that path again. We need more modern images. South Africa and Rwanda spring to mind.
There are also a ton of Youtube videos of various American policemen roughing up (beating) various people they don't like for whatever reason. Some stills from some of those videos will go a long way in showing the average American "low information" type that it can and does happen here already, albeit on a small scale. It only remains for us to get them questioning whether the same thugs who'll do this now, when it's patently against the law and frowned upon, won't ramp up their activities once it's no longer either of those things.