Republican U.S. presidential candidate Donald Trump holds up a crying young child from the crowd as he arrives at a Trump campaign rally in New Orleans, Louisiana March 4, 2016. REUTERS/Layne Murdoch Jr. TPX IMAGES OF THE DAY - RTS9DNN

Republican U.S. presidential candidate Donald Trump shows off the size of his hands as rivals Marco Rubio (L) and Ted Cruz (R) look on at the start of the U.S. Republican presidential candidates debate in Detroit, Michigan, March 3, 2016. REUTERS/Jim Young - RTS97MX

Republican presidential candidate Donald Trump addresses members of the National Rifle Association during their NRA-ILA Leadership Forum during at their annual meeting in Louisville, Kentucky, May 20, 2016. REUTERS/John Sommers II TPX IMAGES OF THE DAY - RTSF87S

Republican U.S. presidential candidate Donald Trump appears onstage in a blaze of lights at the Republican National Convention in Cleveland, Ohio, U.S. July 18, 2016. REUTERS/Mike Segar TPX IMAGES OF THE DAY - RTSIMAH

U.S. Republican presidential candidate, real estate mogul and TV personality Donald Trump poses with his family after formally announcing his campaign for the 2016 Republican presidential nomination during an event at Trump Tower in New York June 16, 2015. The Trump family from L; Eric Trump and his wife Lara, Donald Trump, son Barron, Melania Trump, Vanessa Haydon and her husband Donald Trump Jr., children Kia Trump and Donald Trump III, Ivanka Trump and her husband Jared Kushner and Tiffany Trump. REUTERS/Brendan McDermid - RTX1GS77

U.S. Republican presidential candidate Donald Trump reacts to an answer his wife Melania gives during an interview on NBC's "Today" show in New York, April 21, 2016. REUTERS/Brendan McDermid TPX IMAGES OF THE DAY - RTX2B0OB

U.S. Republican presidential candidate Donald Trump looks to the ceiling referencing the height of a promised immigration wall during a rally at the The Myrtle Beach Sports Center in Myrtle Beach, South Carolina, February 19, 2016. REUTERS/Randall Hill TPX IMAGES OF THE DAY - RTX27QOQ

Audience member Robin Roy (C) reacts as U.S. Republican presidential candidate Donald Trump greets her at a campaign rally in Lowell, Massachusetts January 4, 2016. REUTERS/Brian Snyder TPX IMAGES OF THE DAY - RTX211IR

Republican U.S. presidential candidate Donald Trump introduces Indiana Governor Mike Pence (L) as his vice presidential running mate in New York City, U.S., July 16, 2016. REUTERS/Brendan McDermid - RTSIASS

U.S. Republican presidential candidate, real estate mogul and TV personality Donald Trump arrives by escalator inside at Trump Tower to announce his campaign for the 2016 Republican presidential nomination in New York June 16, 2015. REUTERS/Brendan McDermid - RTX1GRJP

A woman smiles after getting an autograph by U.S. Republican presidential candidate and businessman Donald Trump on her hat after he spoke at a campaign rally South Point Resort and Casino in Las Vegas, Nevada January 21, 2016. REUTERS/David Becker - RTX23GJB

Secret Service agents surround U.S. Republican presidential candidate Donald Trump during a disturbance as he speaks at Dayton International Airport in Dayton, Ohio, March 12, 2016. REUTERS/Aaron P. Bernstein TPX IMAGES OF THE DAY - RTX28USH

U.S. Republican presidential candidate Donald Trump makes his way through the crowd after addressing a Tea Party rally against the Iran nuclear deal at the U.S. Capitol in Washington September 9, 2015. REUTERS/Jonathan Ernst TPX IMAGES OF THE DAY - RTSDCX

Republican Presidential Candidate Donald Trump greets his wife Melania on stage at the Republican National Convention in Cleveland, Ohio, U.S. July 18, 2016. REUTERS/Jim Young TPX IMAGES OF THE DAY - RTSIMB3

Republican U.S. presidential candidate Donald Trump speaks at a campaign rally two days before the Maryland presidential primary election in front of his personal helicopter after landing at the airport in Hagerstown, Maryland, U.S. April 24, 2016. REUTERS/Jim Bourg - RTX2BGLY

Republican U.S. presidential candidate Donald Trump walks past a teleprompter as he departs after delivering a foreign policy speech at the Mayflower Hotel in Washington, United States, April 27, 2016. REUTERS/Jim Bourg - RTX2BXIG

U.S. Republican presidential candidate Donald Trump speaks to supporters at a campaign rally in Dubuque, Iowa January 30, 2016. REUTERS/Rick Wilking TPX IMAGES OF THE DAY - RTX24QQZ

U.S. Republican presidential candidate Donald Trump gets in his SUV as he departs an event at the police headquarters in Manchester, New Hampshire, February 4, 2016. REUTERS/Carlo Allegri TPX IMAGES OF THE DAY - RTX25HY9

Former Alaska Gov. Sarah Palin (L) points to U.S. Republican presidential candidate Donald Trump (R) as she speaks after endorsing him for President at a rally at Iowa State University in Ames, Iowa January 19, 2016. REUTERS/Mark Kauzlarich TPX IMAGES OF THE DAY - RTX234Z7

Republican U.S. presidential candidate Donald trump and his wife Melania attend the Republican caucus at the 7 Flags Event Center in Clive, Iowa February 1, 2016. REUTERS/Aaron P. Bernstein - RTX250A9

Republican U.S. presidential candidate Donald Trump smiles as protestors hold up a sign reading "No Place for Hate in Maine" during a campaign rally in Portland, Maine March 3, 2016. REUTERS/Joel Page TPX IMAGES OF THE DAY - RTS96PL

Republican U.S. presidential candidate and businessman Donald Trump (C) stands between rivals Senator Marco Rubio (L) and Senator Ted Cruz (R) before the start of the Fox Business Network Republican presidential candidates debate in North Charleston, South Carolina, January 14, 2016. REUTERS/Chris Keane

U.S. Republican presidential candidate Donald Trump tosses off his overcoat as he speaks at a campaign event in an airplane hangar in Rome, New York April 12, 2016. REUTERS/Carlo Allegri TPX IMAGES OF THE DAY - RTX29ODW