There's hidden depths to the Hollywood star usually cast as the dashing leading man, writes John Hiscock.

What you see is what you get with George Clooney. Over the course of 30 major films, and one seminal TV medical drama, the actor has made a career out of being the dashing matinee idol - both on screen and off.

Whether he's playing Danny Ocean, the gang leader in the Ocean 11 heist movies, or meeting fans on the red carpet, the 54-year-old is never less than charm personified. Highly polished and beautifully coiffured (a recent survey revealed that the perfect man would have Clooney's hair), he emulates the devil-may-care nonchalance of a Cary Grant or Clark Gable.

But get him on the subject of Donald Trump - the loud-mouthed billionaire who has divided the Republican party, and mystified the world, with his campaign for the American presidency - and that famous sangfroid disappears.

"This is an election cycle and we tend to go through some craziness," he says when I ask about 'The Donald'. "The idea that this xenophobic, fascist theory that we are going to ban Muslims from our country or we are going to kick 12 million Mexicans back down to the border and build a wall they are going to pay for - none of that is ever going to happen.


"This country isn't going to do that. All this chatter is going to be going around for another two or three months but eventually all the insanity will stop and we will start to talk about issues that really matter."

It may be wishful thinking. Against all expectations, eight months after declaring his candidacy, Trump is still leading the field of Republican nominees, despite, or perhaps because of a series of outrageous pronouncements. This week could be decisive. If Trump sweeps the board when a dozen states and one territory vote on "Super Tuesday", the nomination will almost certainly be his.

But Clooney - a diehard Democrat and a fervent supporter of President Obama - refuses to countenance the thought.

"I feel very confident that, in the end, the issues will matter," he says.

He's currently publicising his latest film, a new Coen Brothers comedy set in the golden age of Hollywood called Hail, Caesar!

Clooney plays veteran movie idol Baird Whitlock, an amiable buffoon who is kidnapped while filming a Ben-Hur style epic, causing a huge problem for studio fixer Eddie Mannix, played by Josh Brolin.

To be honest, the role is not exactly a stretch for Clooney. Not only is he obsessed with old Hollywood but he also has a penchant for practical jokes (he once attached a bumper sticker to Brad Pitt's car that bore the legend "F**k cops") which must have helped him with the film's slapstick scenes.

"I know something about the 1950s," he says. His first father-in-law was Oscar-winner Martin Balsam, and his aunt and uncle, whom he lived with when he moved to LA from his native Kentucky in his 20s, were singer Rosemary Clooney and Oscar-winning actor Jose Ferrer.

"My aunt Rosemary's house was party central for a long, long time and she and Jose would throw these wonderful parties," he recalls. "When he was 20 my father spent the night there drinking with Marlene Dietrich. Gregory Peck and his wife Veronique used to have big parties too ... Jack Lemmon would be playing the piano. It was a fun, exciting time."

When I grew up and was going to the movies they weren't making those Technicolour movies or sword-and-sandals epics, but television showed them all so I would watch Spartacus and Ben-Hur over and over again and those films were so much fun.

"The Robe was always on at Easter and we watched the Wizard of Oz on a black and white television so for years I didn't know that it changed colour halfway through."

Clooney says he based his character in Hail, Caesar! on Victor Mature.

"Victor Mature is one of my favourite performers of all time," he says. "He tried to get into the Los Angeles Country Club but they told him, 'I'm sorry Mr Mature, we don't allow actors as members.' And he said: 'I have 75 films to prove I am not an actor.'

"Those epics are funny but they only work because everyone takes them completely seriously. Why I loved Victor Mature is he still had an accent like he was from New Jersey or the Bronx and his hair was always dyed black and I just love the idea of a guy who says, 'All right, let's go do another one of these sandals movies and then I'll go and hit the golf course'."

The run up to this year's Oscars today (NZT) has been dominated by a row over the absence of any black actors from the shortlist. The Academy of Motion Picture Arts and Sciences has pledged to improve the diversity of the voters who decide the nominations amid criticism by many that studios are simply not making enough films about black people.

Clooney admits he has been guilty of hiring only white actors on the five films he's directed.

"Someone said, 'Well, you haven't directed films with African-Americans in the lead' and that's true, but four out of the five films I've directed have been historical films and you can't really change the race of those people."

He thinks the reforms announced by the Academy are a step in the right direction.

"It's good the Academy is bringing in more diversity and they should and we all agree they need to pay more attention to that," he says.

" It's good they're bringing a lot of younger and more ethnic people into the fray."

Clooney is a veteran campaigner - he supports various charities and brought attention to humanitarian crises like Darfur, Haiti and the 2004 Asian tsunami. At a time when most celebrities are nervous about speaking up on hot-button issues he has been vocal about topics ranging from Iraq to gay rights.

Clooney and his wife, human rights lawyer Amal Alamuddin, occasionally throw parties at their English home on a 2.2ha island in the Thames at Sonning Eye. But they are very different types of get-togethers from the old-style Hollywood parties.

"It's not with a lot of famous people," he says. "It ends up being with a lot of politicians. My wife just got President Nasheed released from solitary confinement in the Maldives after he was jailed for political reasons and he came over to the house to say hello.

"It's less about stars and more about people that she and I work with in other parts of our lives."

They divide their time between their homes in Los Angeles, Italy and England but he admits the major problem for the couple is finding time to see each other.

"We have to figure out our schedules," he says. "Our deal is that neither of us can be away for more than a week and so far, in general, that's worked out pretty well."

They will certainly be together tonight at the Dolby Theatre in Los Angeles as they join the rest Hollywood in the annual back-slapping ceremony. Clooney, of course, will look his usual suave self in black tie. But he has sympathy for Amal.

"It's a difficult thing when you're a woman trying to get ready for a ceremony because it has to be a dress nobody else has worn and hair and makeup has to be right, and I'm playing basketball until half an hour before we have to go," he says. "It's really not fair on her."

Clooney on

Donald Trump

Eventually all the insanity will stop and we will start to talk about issues that really matter.

Hollywood and race

It's good the Academy is bringing in more diversity and they should.

On his marriage with human rights lawyer Amal Alamuddin

Our deal is that neither of us can be away for more than a week.