Photos: Republicans debate in Colorado

Ben Carson watches as Donald Trump takes the stage during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Ben Carson watches as Donald Trump takes the stage during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Ben Carson, right, watches as Donald Trump speaks during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Ben Carson, right, watches as Donald Trump speaks during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Republican presidential candidate, former Florida Gov. Jeb Bush speaks during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Republican presidential candidate, former Florida Gov. Jeb Bush speaks during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

John Kasich speaks during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

John Kasich speaks during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

John Kasich makes a point during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

John Kasich makes a point during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Republican presidential candidate, Sen. Rand Paul, R-Ky., speaks during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Republican presidential candidate, Sen. Rand Paul, R-Ky., speaks during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Ben Carson speaks during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Ben Carson speaks during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Mike Huckabee, left, speaks as Jeb Bush, center and Marco Rubio look on during the CNBC Republican presidential debate at the University of Colorado, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Mike Huckabee, left, speaks as Jeb Bush, center and Marco Rubio look on during the CNBC Republican presidential debate at the University of Colorado, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Ted Cruz talks about the mainstream media during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Ted Cruz talks about the mainstream media during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Jeb Bush, left, speaks as Marco Rubio looks on during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Jeb Bush, left, speaks as Marco Rubio looks on during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Rand Paul, right, speaks as Chris Christie looks on during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Rand Paul, right, speaks as Chris Christie looks on during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Ted Cruz, center, speaks as Carly Fiorina, left, and Chris Christie listen during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Ted Cruz, center, speaks as Carly Fiorina, left, and Chris Christie listen during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Republican presidential candidate, businesswoman Carly Fiorina speaks during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Republican presidential candidate, businesswoman Carly Fiorina speaks during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Republican presidential candidates, from left, John Kasich, Mike Huckabee, Jeb Bush, Marco Rubio, Donald Trump, Ben Carson, Carly Fiorina, and Ted Cruz take the stage during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Republican presidential candidates, from left, John Kasich, Mike Huckabee, Jeb Bush, Marco Rubio, Donald Trump, Ben Carson, Carly Fiorina, and Ted Cruz take the stage during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Marco Rubio, right, and Jeb Bush, argue a point during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Marco Rubio, right, and Jeb Bush, argue a point during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Carly Fiorina speaks during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Carly Fiorina speaks during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Donald Trump speaks during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Donald Trump speaks during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Chris Christie makes a point during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Chris Christie makes a point during the CNBC Republican presidential debate at the University of Colorado, Wednesday, Oct. 28, 2015, in Boulder, Colo. (AP Photo/Mark J. Terrill)

Julian Dreiman of Boulder, Colo., holds up sign in the free speech zone on the campus of the University of Colorado before the Republican presidential debate Wednesday, Oct. 28, 2015, in Boulder, Colo. Several protests were being staged across the campus as Republican candidates faced off in the Coors Events Center. (AP Photo/David Zalubowski)

Julian Dreiman of Boulder, Colo., holds up sign in the free speech zone on the campus of the University of Colorado before the Republican presidential debate Wednesday, Oct. 28, 2015, in Boulder, Colo. Several protests were being staged across the campus as Republican candidates faced off in the Coors Events Center. (AP Photo/David Zalubowski)

Giant puppets of Republican presidential candidates Marco Rubio and Jeb Bush are displayed in the

Giant puppets of Republican presidential candidates Marco Rubio and Jeb Bush are displayed in the “Free Speech Zone” outside of the GOP presidential debate on Wednesday, Oct. 28, 2015, at the Coors Event Center on the University of Colorado campus in Boulder, Colo. (Jeremy Papasso/Daily Camera via AP) NO SALES; MANDATORY CREDIT

A giant Donald Trump puppet is displayed in the

A giant Donald Trump puppet is displayed in the “Free Speech Zone” outside the venue of the GOP presidential debate on Wednesday, Oct. 28, 2015, at the Coors Event Center on the University of Colorado campus in Boulder, Colo. (Jeremy Papasso/Daily Camera via AP) NO SALES; MANDATORY CREDIT