The cynical among us assume that a guy who bankrupted his business, cheated on his first wife and humiliates celebrities for a living wouldn't have much of a shot at the Republican presidential nomination.

But even though Donald Trump has turned the celebrity press' fascination with him into leading poll results among contenders for the GOP nod, his repeated interviews attacking President Obama haven't helped him in the one place TV critics expected.

The ratings for his NBC show Celebrity Apprentice.

Viewership for Sunday's edition of the show was down three tenths of a ratings point from the week before, a 17 percent drop to a series low, according to Deadline Hollywood Daily.

Figures from The Nielsen Company show that Trump scored his highest ratings in recent weeks on March 27, just a few days after his infamous confrontation with Whoopi Goldberg on The View over his insistence that President Obama has not proven his was born in America.

The persistence of that claim, which has been officially debunked for quite some time (the Supreme Court has even refused to hear cases on the matter), has led some to accuse conservatives of using uneasiness over race to fuel opposition to the president. In this scenario, birther-believing conservatives are seen as trying to give voters some reason, however outlandish, to justify their race-based fear of a black president.

Small wonder several black celebrities have spoken out against Trump's tactics, including comics Bill Cosby and Tracy Morgan, unmoved by the mogul's claim that he has "always had a great relationship with the blacks."

Since March 27, ratings for The Apprentice have declined, despite steady media coverage of Trump and his allegations, dropping from that high of 9.5-million viewers to 8.2-million people on April 10. Among those aged 25 to 54, the audience dropped from 5.4-million to 4.5-million in the same time period.

Even as some critics blame NBC for pumping up Trump's media blitz by covering it several times on the Today show and other news platforms, the ratings show he may have crossed a line with viewers -- who are watching the show less despite the building drama which saw legendary nutcase Gary Busey ejected from the show Sunday.

This morning, he told NBC White House correspondent Savannah Guthrie he would force OPEC to lower oil prices and bring jobs back to the United States. How exactly? That was left unsaid, as Guthrie seemed to give up on pinning down Trump halfway through the interview, allowing him to act as if the presidency featured a magic wand anyone can wave to make their desires reality.

Given these ratings, NBC probably wishes Trump would go back to overseeing bad beauty pageants and needling Rosie O'Donnell.

Because, even if his latest campaign wins him cachet with conservatives, it's not winning over the TV audience. And for a network TV star, that may be the most important constituency of all.

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