George Clooney is not only one of America’s finest actors (he won an Academy Award for Syriana and was nominated for his leading role in Up in the Air); but he has now directed four feature films, two of which he co-wrote.

In between films he seems to divide his time between international humanitarian work and politics. It’s not surprising then that both Good Night and Good Luck, and his latest film, The Ides of March, are political thrillers. But whereas Good Night and Good Luck, a period film about McCarthyism, reflected Clooney’s liberal views unambiguously, The Ides of March is a much darker, and more pessimistic, film about the nature of politics itself.

The title foreshadows the lethal nature of the political campaign we’re about to experience as the handsome, young Stephen Meyers (Ryan Gosling) delivers the kind of inspirational liberal campaign speech we’d expect from the Left Wing. But the duplicitous nature of politics is present from the start, because Meyers isn’t the frontrunner himself in the Ohio Democratic Primary, Governor Mike Morris’s (Clooney), but his spokesman standing in for him.

While Meyers is all idealism and hope, his boss, campaign manager Paul Zara (the great Philip Seymour Hoffman), is all business, imposing reality checks on Meyers throughout the film. And when we realise how little Meyers knows about the man he worships, those reality checks are no bad thing. When Meyers, high on the excitement of the primary, is flattered into meeting with the cunning Tom Duffy (Paul Giamatti), Zara’s cutthroat counterpart in the opposing camp, his fate is sealed. Meyers heads towards a parallel disaster when he begins an affair with campaign intern Molly Stearns (Evan Rachel Wood). She reveals a couple of secrets that could ruin his career if Duffy already hasn’t. But Meyers is learning fast. He realises Molly’s secrets could offer him a life line if he can play with fire and blackmail as well as his mentors.

Clooney, and co-writers Grand Heslov and Beau Willimon (who worked in politics), turn Willimon’s play, Farragut North, into a claustrophobic, political thriller that is so riveting you emerge from the cinema as though released from a hypnotic spell. Though contained, it seldom feels like a stage play. Following Meyers through the political intrigue is like trying to escape from a burning house while one by one, the exit doors close around you. At one point, Meyers is like Alice in Wonderland, struggling to find space to manoeuvre in a room that has grown too small for his body. Yet the writing, and the aggressive acting from a powerhouse cast, is almost better than the story deserves. Central to that story is Molly Stearns, but her character, and her pivotal role in the plot, don’t make sense.

Given what we later learn about Molly’s recent sexual experiences on the campaign trail, it seems out of character that she would be in the mood for more office shenanigans. And it’s odd that the daughter of a political bigwig, brought up on politics, would be so naive and hysterical about a scandal that we’ve all seen before. There is something not quite right, and certainly, not quite credible, about her character. The execution of Meyers’ plan, too, is a tad too slick and neat, even for this impressively smooth movie.

In Shakespeare’s play, after Caesar is stabbed by his fellow senators, Marc Anthony comes along to inject some reason, nobility and courage into the mayhem. In The Ides of March, all nobility has been destroyed – and we haven’t even seen the Republicans.