In the series, Spacey plays Francis Underwood, a charming but conniving southern US politician, but insists that Underwood is not based on anyone he might know in reality.
That said, Spacey acknowledges that in order to get things done politicians often need to be "bastards".
"It's interesting how we look now at certain politicians who at the time had reputations for being ruthless or being bastards, like Lyndon Johnson," Spacey says.
"Now all these books are coming out re-examining Johnson and while people are saying he was a bastard and he was diabolical, he got things done. He passed three civil-rights bills in a very short presidency."
The timing couldn't be more ideal for House of Cards to make its debut – and, in a telly first, the entire season of 13 episodes will be released online, on subscription service Netflix, on February 1 (see panel).
In it, Spacey, as Francis Underwood, is the ruthless majority whip in the US House of Representatives, who is passed over for a top job by the new president.
With the help of his wife Claire (Robin Wright), the furious Francis plots to simultaneously undermine the new administration and elevate himself to the top of the political food chain.
Throughout the show, Francis "breaks the fourth wall" by addressing the audience, a trick that double Oscar-winner Spacey learned from his recent theatrical run as Shakespeare's Richard III.
"That part is all about looking into the audience's eyes and making them a co-conspirator," the 53-year-old explains. "You could see they were leaning on the edge of their seats and relishing that they felt like they were 'in on it' and part of a secret.
"The audience becomes the ones with whom Francis shares the most, whom he trusts the most. It's a very intimate feeling."
For Robin Wright, she was equally conscious of not basing her Lady Macbeth-type character on any high-profile political spouse.
"I don't know if the character is a realistic portrayal and it would be so presumptuous for someone to say unless they're close friends with someone like Hillary Clinton," she says.
"We only know what we're fed by the media and half of that is probably complete bullshit. So I didn't want to use that as a template."
Wright adds that the role of Claire was a refreshing break from the typical 'long-suffering wife' roles that usually come her way and about which she has expressed her frustration in the past. Why does Wright think she was typecast so often?
"People will respond to a particular quality or style in the way you convey a woman," she replies. It's like, 'I like when she does that', or, 'I like when Sandra Bullock does the Miss Congeniality thing'.
"It's so pat and safe, and then they can't see you do something else. Then you get locked in that cycle."
The 46-year-old has been in the business for 30 years now, and, by her own admission, is still best known for her part in The Princess Bride.
Others, however, will remember her as Jenny in Forrest Gump, or for three films she made here in Ireland, including The Playboys (1992).
'That accent was such a bitch!" she laughs. "We were filming in Redhills in Cavan. It was right below the Border. We had to go through a checkpoint every morning. I was breastfeeding and totally exhausted. They would pull me out of the car every time and search under the seats."
Wright is also well-known for her real-life part as Sean Penn's wife for 14 years, with whom she has a 21-year-old daughter and 19-year-old son.
The couple divorced in 2010, and Wright has since been linked to actor Ben Foster. She took a break from acting to raise her kids just as her career was on the rise in the mid-'90s. She doesn't seem to have any regrets, though.
"I did work less because I wanted to be a mom," she explains. "That was a no-brainer. But I'm still working, my kids are grown and I've worked more in the last three years than I ever have."