Carson Cruz Rubio Trump Iowa Dec 7-10 2015 (Bloomberg/Des Moines Register survey of 400 likely Iowa GOP caucusgoers, conducted December 7–10, 2015, margin of error ±4.9) (Bloomberg/Des Moines Register survey of 400 likely Iowa GOP caucusgoers, conducted December 7–10, 2015, margin of error ±4.9) Next Image