How much would you pay for dinner with George Clooney? A fundraising meal at the Hollywood star's Los Angeles home is set to raise a record $12 million for President Obama's re-election campaign.

George Clooney (Getty)

George Clooney is hot property. What with his humanitarian campaign on Sudan, even getting arrested to draw attention to the bombing of refugees in the Nuba valley, the Hollywood star is the ultimate silver-screen idol turned real.

So hot, in fact, that a dinner to raise money for President Obama at his Los Angeles home is expected to be the biggest presidential fundraiser ever held, netting a possible $12 million in a single night.

150 guests have paid $40,000 a head for the privilege, while millions more have been raised through an online competition, where supporters were asked to donate at least $3 for the chance to win tickets at the very same table as Clooney and Obama.

Obama, Clooney and You

Emails about the contest were relentless: supporters found their inboxes bombarded with "Clooney, Obama and You" messages, exhorting them to pitch in. "You'll automatically be in the running to join me and George Clooney at his place on May 10th", quipped the President. "It's not often I get away from work, so I look forward to spending a fun evening in LA with a couple supporters like you."

Demand for the event was so intense that at one stage, organisers thought of confining it to people living in the immediate area. Clooney told the Wall Street Journal last month that they had already raised around $10 million, "which is about double anything that's ever been done before. All I know is that it's the biggest fundraiser to date - ever."

Most importantly, it has provided a much needed opportunity for the Obama campaign to reach out to millions of grassroots supporters, especially young people who they need to provide some energy and excitement into the autumn.

A cool $12 million would also come in handy in the face of the voracious fundraising efforts by Republican groups like American Crossroads, set up by party guru Karl Rove. Obama's campaign chief David Axelrod told Politico that it would take 181,000 of their small time donors to match an anonymous $10m donation to Crossroads which came through the other week. "So George is pitching in here, and lending his name to this event, and himself to this event. It's really helpful to us."

Starmageddon

Most details about the event have been kept strictly under wraps. The website TMZ revealed, exclusively, that the celebrity chef Wolfgang Puck would be behind the menu, commenting wistfully: "The food is going to be a lot better than the Oscars."

The guest list, too, is top secret, but Obama's big name Hollywood fans are legendary, from moguls Harvey Weinstein and Jeffrey Katzenberg, to actors like Scarlett Johansson, Halle Berry and Reese Witherspoon. What with A-listers like that, plus the presidential entourage, residents living near the Clooney mansion in Studio City are calling it "starmageddon".

It has been something of a tricky week for Obama, amid a furore over his 'evolving' support for gay marriage. But although Clooney himself has proved a strong advocate for same-sex couples, he believes in standing by his man. "I'm a firm believer in sticking by and sticking up for the people whom you've elected", he told ABC television last year. "I'm disillusioned by the people who are disillusioned by Obama, quite honestly."

For the Republicans, it is a chance to poke fun at what they call the president's celebrity status; a tactic they deployed back in 2008, with admittedly limited effect. This time, though, Crossroads has brought out an online ad, asking: "After four years of a celebrity president, is your life any better?"

Too cool for school?

They're not just using the Clooney dinner. A few weeks back, Obama appeared on the Jimmy Fallon show, taking part in a slow-jamming session. That's a slow tempo rhythm and blues ballad, for anyone who isn't familiar. Obama managed to set his talking points on student loan rates to the beat, while Fallon hung out on set, describing him as "the Preezy of the United Steezy".

Definitely cool. But the Republicans siezed the clip for another campaign ad, The Tale of Two Leaders, contrasting the Preezy with a clip of Mitt Romney speaking earnestly about the economy. Grown up, or dude: who, they asked, should be leader of the free world?

One hot Hollywood star, plus one cool president, though, means the kind of occasion to which even Hollywood is rarely accustomed. Reports of impending traffic chaos are posted regularly on Twitter. Details of that closely-guarded guest list are the subject of endless speculation.

Twelve million dollars for dinner with George? Easy. All in a night's work.

Felicity Spector writes about US affairs for Channel 4 News