By Lizo Mzimba
Entertainment correspondent, BBC News
Will Smith compares Obama to Nelson Mandela
Will Smith is in London promoting his latest film Hancock - the story of a failed superhero.
But as well as discussing the movie, he is more than happy to talk about the man who he regards as a political superhero, presidential hopeful Barack Obama.
He chooses carefully the people he gives his support to, with Obama one of the few people who falls into that category.
Smith goes as far as to compare him to one of the great political figures of the last 50 years.
'Pretty good judge'
"Nelson Mandela is kind of the one person I've said yes to. And Barack Obama was probably only the second person that I've really to this level said yes to.
"And that's because I believe what he believes in.
"I travel around the world a lot, and I was kind of used to people being happy when the Americans showed up. That sort of changed over the last eight years," says the actor.
"So I'm excited about the new possibilities of hope and change that Barack is bringing."
The film star also explains why he thinks people in his position should get involved with and try to influence people when it comes to politics.
"Individuals have to decide what they want to do," he says.
"I think I'm a pretty good judge if someone's a good person. So I just lend my support to people that I believe are good people."
He is not the only Hollywood star in the Hancock cast who feels this way.
South African-born Charlize Theron, who can vote in the US for the first time this year, is also a big supporter.
"I'm very excited because what a really historical moment to be voting this year with someone like Barack Obama in the running.
"He's my man, definitely. Whatever happens [I've] just been really, really inspired by him."
So how has Obama managed to get the support of some of Hollywood's top stars?
"He has the ears, we both share the ears," reveals Smith, pulling them out. "People dig the ears."