NBC News NOW — Iowa Caucus Special

Chuck Todd, Dave Wasserman, Ann Selzer, Mary Katherine Ham, Hogan Gidley, Carlos Curbelo, and David Plouffe analyze the Iowa caucuses. Topics discussed include Trump's dominance in the caucus, the impact of a former president's record on the race, the Iowa caucus results and potential agreements, and the differences between the caucus systems in Iowa and New Hampshire.