Overview: AOC breaks down the actual costs of climate change. Sarah Kendzior LIVE on Barr's summary of the Mueller report. An undercover investigation reveals how the NRA responds after a massacre. An NRA official reached out to a Sandy Hook conspiracy theorist after the Parkland shooting. Federal Prison Consultant Justin Paperny LIVE on what he's told the college cheating scandal suspects. A new Deomocratic Congressional Campaign Committee policy stifles primary challengers.