As the young survivors of the Florida school shooting keep up their marches and walkouts for gun control, the NRA is pushing back with its own go-to narrative: “The only thing that stops a bad guy with a gun is a good guy with a gun.”In the aftermath of the Parkland shooting, lots of schools seemed to agree with that approach and moved to put more "good guys" in the classroom. This week, Gianna Toboni sees firsthand how some teachers are taking up arms and explores the deep divisions in America that make stopping these mass shootings seem nearly impossible.See VICE on HBO every Friday at 7:30 p.m. and 11 p.m.