Photos: Republican presidential debate in Las Vegas
Ben Carson, left, and Donald Trump laugh during the Republican presidential debate at the Venetian Hotel & Casino in Las Vegas.
(John Locher / Associated Press)John Kasich makes a point during the Republican presidential debate at the Venetian Hotel & Casino in Las Vegas.
(John Locher / Associated Press)Republican presidential candidates, from left, John Kasich, Carly Fiorina, Marco Rubio, Ben Carson, Donald Trump, Ted Cruz, Jeb Bush, Chris Christie, and Rand Paul respond to debate moderator Wolf Blitzer, far left, during the Republican presidential debate at the Venetian Hotel & Casino in Las Vegas.
(John Locher / Associated Press)Republican presidential candidate Florida Sen. Marco Rubio gestures during the Republican Presidential Debate in Las Vegas, Nevada.
(Robyn Beck / AFP / Getty Images)Republican presidential candidate retired neurosurgeon Ben Carson gestures as he speaks during the Republican Presidential Debate in Las Vegas.
(Robyn Beck / AFP / Getty Images)Republican presidential candidate U.S. Sen. Ted Cruz speaks during the Republican presidential debate on in Las Vegas.
(Justin Sullivan / Getty Images)Republican presidential candidate Jeb Bush speaks during the Republican presidential debate on in Las Vegas.
(Justin Sullivan / Getty Images)Donald Trump makes a point during the CNN Republican presidential debate at the Venetian Hotel & Casino in Las Vegas.
(John Locher / Associated Press)Republican presidential candidate Kentucky Sen. Rand Paul gestures as he takes the stage at the start of the Republican Presidential Debate in Las Vegas.
(Robyn Beck / AFP / Getty Images)Republican presidential candidates Donald Trump, left, and Sen. Ted Cruz shake hands as they are introduced during the Republican presidential debate in Las Vegas.
(Ethan Miller / Getty Images)Carly Fiorina, left, responds to a question from debate moderator Wolf Blitzer during the Republican presidential debate at the Venetian Hotel & Casino in Las Vegas.
(John Locher / Associated Press)Chris Christie speaks during the CNN Republican presidential debate at the Venetian Hotel & Casino in Las Vegas.
(John Locher / Associated Press)Republican presidential candidates, from left, John Kasich, Carly Fiorina, Marco Rubio, Ben Carson, Donald Trump, Ted Cruz, Jeb Bush, Chris Christie, and Rand Paul take the stage during the Republican presidential debate at the Venetian Hotel & Casino in Las Vegas.
(Mark J. Terrill / Associated Press)Republican Presidential candidates (left to right) George Pataki, Mike Huckabee, Rick Santorum, and Lindsey Graham arrive on stage before the start of the under card Republican Presidential debate at The Venetian hotel in Las Vegas.
(L.E. Baskow / AFP / Getty Images)George Pataki, left, makes a point as Mike Huckabee looks on during the CNN Republican presidential debate at the Venetian Hotel in Las Vegas.
(John Locher / Associated Press)Republican presidential candidate Mike Huckabee speaks during the CNN Republican presidential debate Las Vega
(Justin Sullivan / Getty Images)The under card Republican Presidential debate held at The Venetian hotel in Las Vegas.
George Pataki speaks during the Republican presidential debate at the Venetian Hotel & Casino in Las Vegas.
(John Locher / Associated Press)Former Republican Presidential candidate Lindsey Graham gestures on stage during the under card Republican Presidential debate at The Venetian hotel in Las Vegas.
(Robyn Beck / AFP / Getty Images)Republican Presidential candidate Rick Santorum gestures on stage during the under card Republican Presidential debate at The Venetian hotel in Las Vegas.
(Robyn Beck / AFP / Getty Images)Republican Presidential candidates (left to right) George Pataki, Mike Huckabee, Rick Santorum, and Lindsey Graham arrive on stage before the start of the under card Republican Presidential debate at in Las Vegas.
(L.E. Baskow / AFP / Getty Images)