"Barack Obama: he's going to be the biggest disappointment EVER!" So said Chris Addison at his gig in London last Saturday night – and the atmosphere in the room curdled. Addison – by no means a confrontational comic – backtracked instantly. ("No, I mean – It's exciting, obviously ...") But it brought into focus the problem with which comics worldwide are currently grappling. Should they joke about Obama and poop the world's party? And if so, how?

US comics have been candid about their concerns. Here's Bill Maher, former host of Comedy Central's Politically Incorrect, on the president-elect: "Here's a guy who's not fat, not cheating on his wife, not stupid, not angry and not a phoney. Who needs an asshole like that around for the next four years?" Or Scot-turned-American Craig Ferguson, now presenter of CBS's The Late Late Show (although he'll always be Bing Hitler to me): "A dignified African-American man – what the hell can I do with that?" His conclusion? "My only hope is Biden!"

This comedy crisis is magnified by the imminent exit stage right of George Bush, generally held to have been a spurting oil geyser of gags these last eight years. In fact, Bush-baiting was a busted flush within six months of Dubya's first term: "one of his most daunting achievements," as Ryan Gilbey writes this week in the New Statesman, "[was] to present to the world a version of himself more pitiful than anything the satirists could construct." It got to the point, watching standup, when I longed to hear jokes supporting Bush and his world-view – anything to upset the "he's evil and stupid" consensus.

But if comedy's job is to subvert accepted wisdom, shouldn't stand-ups be bursting the Barack bubble? Well, not necessarily – comedians are human too, and deserve this moment, like everyone else, to recharge their optimism. (Most of them will be broadly supportive of Obama's politics – at least until his inevitable compromises kick in.) But that doesn't stop us speculating what the nature of the jokes will be when Obama's sheen wears off.

The funniest so far have been at The Onion website, whose spoof headlines have included Black Man Given Nation's Worst Job and Nation Finally Shitty Enough to Make Social Progress – both of which joke about America's racism rather than Obama per se. That racism, of course, makes Obama humour a delicate affair – at least for white comics. His election has already prompted calls for more black comedians in the mainstream – on Saturday Night Live, for example, where, while Tina Fey was aping her lookalike Sarah Palin, Obama has been played by Fred Armisen, who is not African-American.

On stage at an LA comedy club last weekend, meanwhile, black stand-up Tommy Davidson performed "a bit from Obama's upcoming inaugural speech." He stood at an imaginary lectern – then a shot rang out, and he dropped dead. Ho ho ho!

As if to add to comedians' frustration, Obama himself has proved no mean joker. "Contrary to the rumours you have heard, I was not born in a manger," he quipped while on the campaign trail. "I was born on Krypton and sent here by my father, Jor-el, to save the planet Earth." Here, the joke is on Obama's supposed messiah status – and I suspect that, when the dust settles, this might be comedy's line of attack. Obama's grandiose acceptance speech last week could only have been made by a man with high self-regard.

Some comics are already in on the act, poking fun at his perceived rectitude and sense of entitlement. "The presidential debate," reported talk-show host Jay Leno mid-campaign, "was a town-hall format, which is John McCain's favourite way to speak to crowds. As opposed to Obama's favourite way, a sermon on the mount." The tougher the going gets as president, the more a messianic air would grate. (Remember Blair, the vicar of St Albion? With whom, praise the Lord, Obama seems otherwise to have little in common.) And soon, of course, there will be actions to joke about, not just airy-fairy promises. Normal service will duly be resumed. In the meantime, let Obama – and the rest of us - enjoy the amnesty.