The eco-themed science fiction movie Avatar helped cement James Cameron's standing as one of Hollywood's most strident environmentalists.
Now, in a gesture that perfectly captures the fractious spirit of a polarised nation, comes the inevitable backlash: a political attack advert entitled "James Cameron – Hypocrite".
A week ago, it emerged that the Oscar-winning film director had put his money where his mouth is by donating $1m of his personal fortune to opponents of Proposition 23, a ballot measure facing voters in California at the coming mid-term elections which would suspend the state's landmark law combating climate change. Supporters of the proposition weren't going to take that lying down, though. On Thursday, they returned fire by releasing a short film that claims to highlight a Titanic-sized gulf between Mr Cameron's somewhat magisterial proclamations regarding the importance of combating climate change, and his actual lifestyle.
"He's fighting Proposition 23 because he says we should use less fossil fuel," notes the film. "But if Cameron succeeds, it will mean higher prices and job losses." It proceeds to quote a recent newspaper interview in which he discussed global warming, telling a reporter that "we are going to have to live with less". The camera then cuts to aerial footage of the three adjacent homes that Cameron inhabits in the hills of Malibu. Although they each have heated swimming pools, and together boast more than 24,000 sq ft of living space, the properties have not a single energy-saving solar panel or windmill between them. "He also owns a 100-acre ranch in Santa Barbara, a JetRanger helicopter, three Harleys, a Corvette, a Ducati, a Ford GT, a collection of dirt bikes, a yacht, a Humvee fire truck, and a fleet of submarines," continues the narrator. "And yet he demands WE live with less? James Cameron: HYPOCRITE."
Although the film conveniently ignores the fact that Cameron pays to off-set his personal carbon emissions, its aggressive tone will concern many of Hollywood's liberal elite, who preach green living while driving Porsches and clocking up the air miles in first class. In its first two days, the attack ad clocked-up 120,000 views on YouTube.
Mr Cameron is hardly the only prominent celebrity to oppose the ballot measure. Other high-profile individuals campaigning against it include David Arquette, Benjamin Bratt, and California's Governor, Arnold Schwarzenegger – a prime candidate for a similar attack advert, since he drives an SUV and commutes to Sacramento from his home in Los Angeles by private jet.
In the current economic climate, knocking the lifestyles of the rich and famous is likely to strike a chord. And given the brouhaha that greeted revelations about Al Gore's carbon footprint, the makers of "James Cameron – Hypocrite", who in 2009 produced a contentious documentary disputing climate change called Not Evil Just Wrong, may be tapping a rich rhetorical vein.
Behind the point-scoring lies an important political battle. Proposition 23 seeks to suspend AB 23, California's tough greenhouse-reduction law, until unemployment in the state drops below 5.5 per cent for four consecutive quarters, a figure that is virtually unobtainable. It was somewhat cynically financed by Tesoro and Valero, two oil companies based in Texas.
The ballot measure is one of many facing voters at the 2 November elections which have been sponsored by corporations exploiting a recent relaxation of funding rules by the US Supreme Court, which gave private firms the right to donate money (anonymously, if they want) to single-issue advocacy groups. That ruling has led to an explosion in the number of negative advertisements flooding the airwaves in this election season. A record $3bn will have been spent on adverts, most of which endorse right-wing causes, by the time that voters head to the polls in nine days' time.
At present, polls suggest that Proposition 23 will be closely fought, with a slim majority of voters in California currently opposing it. However, the oil industry may take comfort in the fact that all of those polls were conducted several days before "James Cameron – Hypocrite" was released.