GOP candidates debate

Republican U.S. presidential candidates businessman Donald Trump (L) and U.S. Senator Ted Cruz (R) applaud Dr. Ben Carson (C) at the debate held by Fox Business Network for the top 2016 U.S. Republican presidential candidates in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Jim Young

Donald Trump (L) listens as Dr. Ben Carson (R) speaks during the debate held by Fox Business Network for the top 2016 U.S. Republican presidential candidates in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Jim Young

Dr. Ben Carson (L) listens as Ted Cruz speaks at the debate held by Fox Business Network for the top 2016 U.S. Republican presidential candidates debate in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Darren Hauck

John Kasich speaks at the debate held by Fox Business Network for the top 2016 U.S. Republican presidential candidates debate in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Darren Hauck

John Kasich, Jeb Bush, Marco Rubio, Donald Trump, Dr. Ben Carson, Ted Cruz, Carly Fiorina and Rand Paul pose during a photo opportunity before the debate held by Fox Business Network for the top 2016 U.S. Republican presidential candidates in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Jim Young

Donald Trump (L) listens as rival candidate Dr. Ben Carson speaks during the debate held by Fox Business Network for the top 2016 U.S. Republican presidential candidates in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Darren Hauck

John Kasich, Jeb Bush, Marco Rubio, Donald Trump, Dr. Ben Carson, Ted Cruz, Carly Fiorina and Rand Paul participate in the debate held by Fox Business Network for the top 2016 U.S. Republican presidential candidates in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Darren Hauck

Donald Trump gives a thumbs up as he stands next to Dr. Ben Carson (R) at the start of the debate held by Fox Business Network for the top 2016 U.S. Republican presidential candidates in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Jim Young

Marco Rubio speaks as he debates Donald Trump (C) and Dr. Ben Carson (R) at the debate held by Fox Business Network for the top 2016 U.S. Republican presidential candidates in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Jim Young

Jeb Bush (L) speaks as Marco Rubio (R) looks on during the debate held by Fox Business Network for the top 2016 U.S. Republican presidential candidates in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Jim Young

Donald Trump listens to the U.S. National Anthem prior to the the debate held by Fox Business Network for the top 2016 U.S. Republican presidential candidates in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Jim Young

Ted Cruz (L) applauds Carly Fiorina (C) as she waves next to Rand Paul (R) at the debate held by Fox Business Network for the top 2016 U.S. Republican presidential candidates in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Jim Young

Donald Trump (L) listens as rival candidate Dr. Ben Carson speaks during the debate held by Fox Business Network for the top 2016 U.S. Republican presidential candidates in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Jim Young

Republican U.S. presidential candidates (L-R) former U.S. Senator Rick Santorum, New Jersey Governor Chris Christie, former Arkansas Governor Mike Huckabee and Louisiana Governor Bobby Jindal pose during a photo opportunity before the start of a forum held for lower polling candidates held by Fox Business Network before their 2016 U.S. Republican presidential candidates debate in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Jim Young

Rick Santorum, Chris Christie, Mike Huckabee and Bobby Jindal debate during a forum for lower polling candidates held by Fox Business Network before the 2016 U.S. Republican presidential candidates debate in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Jim Young

Chris Christie, Mike Huckabee and Bobby Jindal debate during a forum for lower polling candidates held by Fox Business Network before the 2016 U.S. Republican presidential candidates debate in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Jim Young

Rick Santorum (L) and Chris Christie pose together before the start of a forum for lower polling candidates held by Fox Business Network before the U.S. Republican presidential candidates debate in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Darren Hauck

Chris Christie laughs as Mike Huckabee (R) speaks at a forum for lower polling candidates held by Fox Business Network before the U.S. Republican presidential candidates debate in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Darren Hauck

Mike Huckabee speaks at a forum for lower polling candidates held by Fox Business Network before the U.S. Republican presidential candidates debate in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Darren Hauck

Rick Santorum speaks during a forum for lower polling candidates held by Fox Business Network before the U.S. Republican presidential candidates debate in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Darren Hauck

Rick Santorum speaks as fellow candidate Chris Christie (R) looks on at a forum for lower polling candidates held by Fox Business Network before the 2016 U.S. Republican presidential candidates debate in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Jim Young

Mike Huckabee gestures at fellow candidate Bobby Jindal (R) as he speaks during a forum for lower polling candidates held by Fox Business Network before the 2016 U.S. Republican presidential candidates debate in Milwaukee, Wisconsin, November 10, 2015. REUTERS/Jim Young