Sometimes, you just have to take the man at his word:
According to Mr. Trump, in his own words, "I do whine because I want to win, and I'm not happy about not winning, and I am a whiner, and I keep whining and whining until I win." (ref. August 11, 2015 interview with CNNs's New Day host Chris Cuomo). Also, in Rich Lowrey's column in the National Review, Mr. Trump was described as "the most fabulous whiner in all of American politics." On the same date 8/11/15, Colin Campbell wrote, "Real-estate developer Donald Trump embraced the idea that he's a 'whiner.'"
http://www.nationalwhinersday.com/most-famous-whiners.html
According to Mr. Trump, in his own words, "I do whine because I want to win, and I'm not happy about not winning, and I am a whiner, and I keep whining and whining until I win." (ref. August 11, 2015 interview with CNNs's New Day host Chris Cuomo). Also, in Rich Lowrey's column in the National Review, Mr. Trump was described as "the most fabulous whiner in all of American politics." On the same date 8/11/15, Colin Campbell wrote, "Real-estate developer Donald Trump embraced the idea that he's a 'whiner.'"
http://www.nationalwhinersday.com/most-famous-whiners.html