Obama will be fêted at a $2,300per-head fundraiser at the Beverly Hills Hotel hosted by Steven Spielberg and his former DreamWorks partners David Geffen and Jeffrey Katzenberg next month.

Hundreds of invitations went out earlier this week to southern California's most generous political donors, including studio heads, Alist actors, directors and producers.

Geffen - at one time so ardent a fan of Clinton's husband Bill that he had a presidential flag pole installed on the terrace of his Malibu beach compound - will hold a smaller, more exclusive event at his home later that same night at which potential "co-chairs" of the Obama campaign will be invited to cough up $46,000 (Euro35,475) each.

The Illinois senator is clearly enjoying his rock-star status, even as people wonder if he can maintain the momentum. While a handful of Hollywood luminaries have pledged their unambiguous support for him - among them George Clooney, Oprah Winfrey, Halle Berry and the politically connected talent agent Ari Emanuel - others are either hedging their bets or waiting.

The first caucuses and primaries are, after all, still a year away.

Of Obama's hosts, only Katzenberg, the animation whizz behind the Shrek films, has offered his full support. Spielberg has said he is backing more than one horse in this race, and might well throw fundraisers for Clinton and John Edwards too.

Clinton, meanwhile, has her own coterie of fans in California, many cultivated during her husband's presidency. She is planning her own fundraiser at a Beverly Hills hotel, to take place in late March, and will swing by on 11 February to meet two key supporters, the television producer Haim Saban (the man behind Power Rangers) and Sim Farar, an investment banker.

In an early show of support, Elizabeth Taylor wrote her a cheque this week for $2,000, saying: "I like the way she thinks." The battle for Hollywood's money is arguably more crucial this time than in any previous election. The working theory is that a viable candidate needs at least $100m to run for the White House in 2008. Hollywood is usually good for $30-$40m, spread over all candidates from both parties.

Obama's challenge to Clinton is likely to be more symbolic than financial - she still has $14m left over from her last Senate campaign in New York and can afford to lose a few contributors here and there. The bigger damage is likely to be inflicted on the clutch of less visible candidates, who need to fill up their coffers fast or contemplate early withdrawal from the race. Of the seven or eight other Democrats indicating an interest in running, only Edwards, who was John Kerry's running mate in 2004, seems to have much fundraising clout at this stage.

Southern California is where the first skirmishes take place as it is the richest source of political money. As one prominent activist and consultant, Rick Jacobs, put it:

"California is the nation's ATM when it comes to presidential primaries. Candidates fly in with pillowcases, clean out our bank accounts then leave to spend weeks with families in Iowa and New Hampshire."

OBAMA OR CLINTON? WHERE HOLLYWOOD STANDS

SO FAR George Clooney: Obama candidacy would be "the most electrifying thing" Jeffrey Katzenberg: DreamWorks boss backs Obama all the way Halle Berry: "would collect paper cups off the ground to make his pathway clear" Steven Spielberg: Hosted Obama dinner but may also do so for others Steve Bing: Producer of 'Beowulf' (and Liz Hurley's ex) is a Clinton man Sherry Lansing: Former studio chief at Paramount is a confirmed Clintonista Elizabeth Taylor (RIGHT): Wrote Hollywood's first cheque to the Clinton campaign