Presidential Candidate Donald Trump Holds Iowa City Campaign Rally [Getty Images]

Donald Trump, president and chief executive of Trump Organization Inc. and 2016 Republican presidential candidate, reacts to a protester during an event in Iowa City, Iowa, U.S., on Tuesday, Jan. 26, 2016. Citing unfair treatment by Fox News, Trump will not participate in the Republican presidential debate on Thursday, his campaign manager told reporters. Photographer: Patrick T. Fallon/Bloomberg via Getty Images

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