Republican presidential candidates Ben Carson, left, and Donald Trump talk before the start of the CNN Republican presidential debate at the Ronald Reagan Presidential Library and Museum on Wednesday, Sept. 16, 2015, in Simi Valley, Calif.
Republican presidential candidates Ben Carson, left, and Donald Trump talk before the start of the CNN Republican presidential debate at the Ronald Reagan Presidential Library and Museum on Wednesday, Sept. 16, 2015, in Simi Valley, Calif. Mark J. Terrill AP
Republican presidential candidates Ben Carson, left, and Donald Trump talk before the start of the CNN Republican presidential debate at the Ronald Reagan Presidential Library and Museum on Wednesday, Sept. 16, 2015, in Simi Valley, Calif. Mark J. Terrill AP