According to Michael Moore, Trump was unhappy with the money he was making as host and star of The Apprentice and The Celebrity Apprentice, and believed a presidential bid — and all the attention it would garner — would prove to NBC that he was worth millions more than what he was being paid. However, Trump's plan immediately backfired when he launched his campaign with an infamous press conference where he called Mexicans "rapists" and "drug dealers," and pledged to build a border wall. NBC immediately fired him.
But as Trump's polls surged, his campaign became a media sensation and he actually started winning, Trump supposedly put aside his search for a better TV deal and relished the near-universal attention. Moore, however, pointed to Trump's uncharacteristically restrained speech after winning the New Jersey primary and clinching the Republican nomination as the moment the ruse finally caught up with him.
Read more in http://www.rollingstone.com/politics/news/michael-moore-donald-trump-never-wanted-to-be-president-w434840