Aly Sheehy is a senior at Marjorie Stoneman Douglas High School, where 17 people were killed in a mass shooting last month. She joins Katie and Brian for an emotional account of how she and her classmates in Parkland, Florida have coped with the tragedy's aftermath and why they are now pushing for change. Katie and Brian also speak with Shannon Watts, the founder of Moms Demand Action, about state and local gun law reforms— and taking on the NRA.