This year’s candidate debates could shape who Democrats pick as a nominee to run against Donald Trump, and now the party is changing some of the rules for who can be in the debates in the middle of the process, drawing criticism from candidates including Sen. Bernie Sanders and Tom Steyer. In this Special Report, MSNBC’s Ari Melber charts the role of debates, the controversial new DNC rule change, the impact on candidates including Mike Bloomberg, and how the DNC’s shift conflicts with statements the party chair Tom Perez made as recently as January, when he said, “we made the rules, they were very transparent, they're very inclusive, and we can't change the rules midstream.”