As chance would have it, productions of Frankenstein are currently on show in both London and New York. Well, in an era in which there is a whole genre of literature devoted to how the internet is enslaving us, it is not surprising that Mary Shelley's tale of a manmade monster overtaking the strength of his master should feel so relevant. What is more surprising is that while one of these productions is happening on the stage, the other is happening [INSERT MENACING MUSIC] in real life!

In London, Danny Boyle's theatrical version has attracted many critical bouquets. But Boyle, prepare for some toxic rain on your thespy parade because the version in New York, while perhaps lacking in British panache, has something poor deprived olde England will never be able to claim as its own: Donald Trump.

Now that Barack Obama has made the shock announcement that, yes, he will run for president in 2012, the Republican party has found itself facing two problems: few of their own particularly desire to enter a presidential race against an incumbent; and the ones who do include Newt Gingrich, Michele Bachmann and Donald Trump.

Gingrich, you may recall, tried to have President Clinton impeached for lying about having an affair while he himself was lying about having an affair. This, he recently explained, was because "driven by how passionately I felt about this country . . . things happened in my life that were not appropriate", or, as the website Wonkette put it, "Newt Gingrich Committed Adultery Because America Made Him Horny." Bachmann is the Tea Partyist who is so patriotic she didn't know in which state the American revolution began. Which leaves the party with Trump.

In the past fortnight, Trump has been shopping himself around to pretty much any news TV programme that'll have him. In the absence of any obvious job title, news editors have universally described him as "Donald Trump: potential presidential candidate." This is how I would like to be described from hereon as I, too, am a potential presidential candidate, as is anyone who was born in the United States. Mariah Carey: potential presidential candidate.

I have known of Trump's presidential ambitions since meeting him at a party for the rhinestone-plated shopping network QVC in LA two months ago. Upon hearing of my provenance ("London? London, England?"), Trump keenly discussed his political plans for 2012, continuing the tradition of announcing one's presidential ambitions at a party for a shopping network, feet away from Kim Kardashian. Trump can currently be seen on TV in the Celebrity Apprentice, bossing around Latoya Jackson and Meat Loaf, which is how FDR prepared for the White House, too.

What to make of a man who presents himself as the Republican's "business candidate" yet has flirted with near bankruptcies? (He has also flirted with the Democrats and independents, but what political candidate hasn't had their youthful dalliances with contraband substances?) Does he really expect anyone to trust the political judgment of a man who insists on calling that small straw hut atop his scalp "hair"? And how will he cope with delicate international negotiations when he was once so riled by a New York Times columnist who dared to describe him as a "financially embattled thousandaire" that he sent her a copy of her column with the editorial addition of the words "Face of a dog!" scrawled beneath her byline photo?

But the real question he presents is also the one he answers: how bad do you have to be before even Fox News won't get behind you?

Trump recently appeared on Bill O'Reilly's programme and managed to make O'Reilly – who once told the son of a 9/11 victim to "shut up" when he refused to support the war in Afghanistan – look reasonable. Much to O'Reilly's scepticism, Trump alleged that he "probably" thought Obama wasn't born in America, which turned out to be not merely code for Obama being Muslim, because Trump stated that he thinks that, too.

Fox News' Glenn Beck talked to O'Reilly about this interview last week and the man who felt very comfortable proclaiming that Obama "is a racist" in 2009 said that Trump's allegations made him "uncomfortable".

"I don't know what that strategy is," Beck, the little innocent, said. "It's to get attention," explained O'Reilly. "But that doesn't help you!" wailed Beck.

The monster has risen! Trump has never been averse to sacrificing his dignity at the altar of attention, but making himself the birther candidate takes his self-sacrificing nature to a new level. It's easy to see how this has happened. Fox News promotes the idea that political credibility is synonymous with radicalised grandstanding, and that attention-seeking is more important than plausibility. This is why it employs the unelectable Sarah Palin and Newt Gingrich, but not the more realistic Republican candidate, Mitt Romney. This is also why, as Gary Younge wrote last week: "What you need to say and do to be credible within the Republican party essentially deprives you of credibility outside it."

Fox is the Frankenstein that has created this Trumpish monster. In that exchange between Beck and O'Reilly, you could see the two highest-profile faces of the channel realise what a hopeless corner they have painted themselves into, and the fact that Beck's "discomfort" with Trump may have something to do with the rumour that Trump may (if he, amazingly, doesn't become president) take over Beck's show only proves the point.

In Shelley's book, the monster and doctor end up destroying one another, not directly but completely. In the case of the hard right and Fox News, the end looks likely to be more intertwined.