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OSKALOOSA, IA - JULY 25:  Republican presidential hopeful businessman Donald Trump speaks to guests gathered for a rally on July 25, 2015 in Oskaloosa, Iowa. During his last visit to the state Trump sparked controversy when he said Senator John McCain (R-AZ), a former POW, was not a war hero.  (Photo by Scott Olson/Getty Images)
OSKALOOSA, IA - JULY 25:  Republican presidential hopeful businessman Donald Trump speaks to guests gathered for a rally on July 25, 2015 in Oskaloosa, Iowa. During his last visit to the state Trump sparked controversy when he said Senator John McCain (R-AZ), a former POW, was not a war hero.  (Photo by Scott Olson/Getty Images)

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