Republican presidential candidates (L-R) New Jersey Gov. Chris Christie, Sen. Marco Rubio, R-Fla., former Florida Gov. Jeb Bush and Sen. Ted Cruz, R-Texas, talk after the Republican presidential primary debate, Thursday, Jan. 28, 2016, in Des Moines, Iowa. (AP Photo/Charlie Neibergall)
Republican presidential candidates (L-R) New Jersey Gov. Chris Christie, Sen. Marco Rubio, R-Fla., former Florida Gov. Jeb Bush and Sen. Ted Cruz, R-Texas, talk after the Republican presidential primary debate, Thursday, Jan. 28, 2016, in Des Moines, Iowa. (AP Photo/Charlie Neibergall) 
