On September 16, 2015, Tapper moderated two Republican primary debates from the Ronald Reagan Presidential Library in Simi Valley, California.[33] The main debate drew an average of 23.1 million viewers, making it the most watched program in the history of CNN and the second most watched primary debate ever.[2] He also moderated the March 10, 2016 Republican presidential debate in Miami, which drew almost 12 million viewers[3] and according to Variety "garnered acclaim for its substance."[4]