Marsden's fatherly advice on role
James Marsden said he called on his dad for reassurance when he was offered the part of President John F Kennedy.
The actor, whose father is a Kennedy buff, plays one half of America's most documented couple in The Butler, but was only given two weeks to prepare for the part.
"I was like, 'I'm too young for this', and he said, 'No, you're perfect - Kennedy might have been a few years older than you, but to the rest of the people in office, he was a kid'," James said.
When director Lee Daniels set him a "homework assignment" to find out something about JFK that very few people know, it was his father he looked to.
"He remembers reading that Jackie bought him an expensive Italian sports car and, behind her back, he had it returned," said James. "He was a man of the people, and never wanted to appear as if he had more than your average American person."
The 40-year-old Ally McBeal, X-Men and Hairspray star said he didn't want to be a mimic in the film, also starring Forest Whitaker and Oprah Winfrey.
"To be honest, I've always been a pretty decent mimic, yet the pitfall for me was not to go in and be a JFK impersonator. No one wants to see that," he said.
"We all know what he and Jackie looked like and how they spoke, so that was a little daunting because everyone's going to have their own expectations, but you have to do your own thing."
:: The Butler is in cinemas now.