Donald Trump owns this Trump Tower building at 725 Fifth Ave. in New York City. It's one of only a handful he owns in the city, though 17 buildings there bear his name. Spencer Platt/Getty Images hide caption

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Donald Trump arrives at the National Federation of Republican Assemblies on Saturday in Nashville, Tenn., ahead of his speech before the conservative group. Mark Humphrey/AP hide caption

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Donald Trump poses for a selfie with a woman wearing a "Team Trump" T-shirt on stage at the National Federation of Republican Assemblies Presidential Preference Convention in Nashville, Tennessee. Jason Davis/Getty Images hide caption

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Mitt Romney peers over the podium at guests being pointed out by his wife, Ann, during an event at which Donald Trump endorsed Romney in 2012. Ethan Miller/Getty Images hide caption

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A security guard for Republican presidential candidate Donald Trump removes Univision anchor Jorge Ramos from a news conference on Tuesday in Iowa. Charlie Neibergall/AP hide caption

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Donald Trump and Fox News are at odds again, after the Republican presidential candidate criticized host Megyn Kelly. "Donald Trump rarely apologizes, although in this case, he should," Fox chief Roger Ailes said. Mark Wallheiser/Getty Images hide caption

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Butler County Sheriff Richard Jones stands next to a illegal aliens sign he had placed in the parking lot of the Butler County Sheriff's Department, Nov. 3, 2005, in Hamilton, Ohio. David Kohl/AP hide caption

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Republican presidential candidate Donald Trump speaks at a press conference Wednesday prior to a town hall meeting at Pinkerton Academy in Derry, N.H. Matthew Healey/UPI/Landov hide caption

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A woman holds signs depicting the head of Republican presidential candidate and businessman Donald Trump as she waits to enter the auditorium to hear him speak on Wednesday in Derry, N.H. Mary Schwalm/AP hide caption

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Donald Trump wears what's become a campaign signature: his "Make America Great Again" hat. Part of making the country great again, Trump says, is implementing his hard-line immigration plan. Scott Heppell/AP hide caption

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Donald Trump continues to lead in the polls and on Sunday released his first policy position — a conservative proposal on immigration. Seth Wenig/AP hide caption

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Sen. Bernie Sanders, I-Vt., has gotten some of the biggest and most devoted crowds of the 2016 presidential race, including in Portland, Ore., this month, where he drew more than 19,000. Troy Wayrynen/AP hide caption

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