Donald Trump the Political Showman, Born on ‘The Apprentice’

He hounded network executives at all hours, demanding Nielsen reports and asking: “How’d we do? How’d we do?”

He routinely fibbed about ratings, declaring “The Apprentice” the No. 1 show on television even when, as NBC officials would sheepishly admit, it was not.

And he demanded a raise to $6 million from roughly $50,000 an episode during a lunch with Jeff Zucker, then head of NBC. It was only fair, he explained, because the cast of NBC’s sitcom “Friends” earned the same amount — combined.

With its glamour and famous catchphrase — “You’re fired” — “The Apprentice,” which debuted in 2004, was the ultimate showcase for Donald J. Trump’s self-styled image as a power-wielding mogul. But it also served as a prequel of sorts for his improbable next act as a presidential nominee, who next week will return to prime time as the ringmaster of the Republican National Convention.

More than Mr. Trump’s real estate deals, the show transformed its star from a New York curiosity into a national sensation, introducing millions of viewers — and, later, voters — to a highly flattering, highly fictionalized version of Mr. Trump, more appealing than the real-life developer whose successes were tempered by bankruptcies and personal turmoil.

Mr. Trump, who had little previous television experience, revealed a showman’s mastery of the medium, which he used this year to confound political opponents and seduce ratings-hungry networks. Those skills will be on full display at the convention in Cleveland, where Mr. Trump is personally wooing celebrities and overseeing stagecraft for a blowout spectacle that will be less C-Span, more MTV.