I CAN hear it in her voice – Annette Bening is struggling to take in what has just happened. “Every time Trump or one of his people say something I’m still stunned,” says the American actor. “I need to get over this – we all do. Then maybe we can find a way to respond.”

It’s a few days after President Donald Trump’s inauguration and like many others in her profession, including Meryl Streep and Robert De Niro, she is appalled at the direction in which the new Commander in Chief is taking her country. Hollywood is perhaps the ultimate incarnation of the privileged liberal elite Trump and his supporters so disdain, of course, and its often eye-watering hypocrisy can make people on both sides of the American political divide cynical.

Bening may well be part of this elite, and indeed one half of a Hollywood power couple – her husband of 25 years is Warren Beatty – but it’s almost impossible to be cynical about her. She’s certainly not part of any vacuous Hollywood conveyor belt; a raft of fiercely intelligent performances over the last 30 years, in films often exploring and questioning facets of the American dream, are testament to that.

She has built up one of the most respected and distinctive bodies of work in the industry, from Postcards From The Edge and Regarding Henry to Running With Scissors, Ginger and Rosa, The Kids Are Alright and her latest film, 20th Century Women, garnering four Oscar nominations, two Golden Globes and a Bafta. She is probably best known, however, for her gut-wrenching portrayal of Carolyn Burnham, the outwardly perfect, inwardly miserable wife of Kevin Spacey in the 1999 Oscar-winning film American Beauty.

Not surprisingly, conversation with Bening reveals her to be thoughtful, intelligent and engaged. It’s not every American film star who could debate the finer points of UK politics and she admits to watching interviews with former Labour leader Neil Kinnock for pleasure.

“I was working in London when the Brexit vote took place,” the 58-year-old tells me on the phone from her home in Los Angeles. “It was extraordinary. I was watching TV when David Cameron resigned live and I experienced first-hand the sense shock that emanated from the vote – people just didn’t see it coming.

“I also saw the division the vote had created, certainly with Scotland voting so strongly against and the possible consequences of that.

“With regard to polling what happened with Brexit was exactly the same as what happened with Trump – no one understood what was happening. At the time I watched a fascinating BBC interview with Neil Kinnock. Thinking about it now he could have been talking about why people here voted Trump: they were voting against their own economic interest, voting out of fear, and the regions and neighbourhoods where immigrant fear was stoked were places where there were actually very few immigrants.”

Beatty, of course, has half a century of political activism under his belt, having campaigned vociferously for the Democrats since Robert Kennedy ran for president in 1968. Bening says she favours a less direct approach than her husband and with events moving so quickly in the US admits she is still considering how best to respond.

“We are in a new reality,” she explains. “The bottom line is that we in the arts have a huge responsibility and I’m going to exercise my right to speak out. But I’m very selective about how I voice my views – I prefer to use the work that I do. We must be careful not to be in a state of denial but on the other hand you have to allow yourself to feel the outrage, the dismay and, quite frankly, the sadness, and build from there.

“Following Trump’s election everybody in the arts started to think about what they were doing in a different way. A lot of the films getting praise at the moment are dealing with issues of poverty, racism, sexism, xenophobia, anti-immigration sentiment, fear – all stuff that is on everyone’s lips – and because of Trump’s election it is being re-contextualised.”

Bening’s role in 20th Century Women, released later this month, is certainly political with a small p. She plays Dorothea, an independent and free-thinking woman in her mid-fifties, a devoted single-parent to feisty teenage son Jamie. The film, written and directed by Mike Mills, is a poignant, often very funny, evocation of a certain time and place in America – southern California in 1979 – and follows Dorothea as she reaches out to others in her circle, including two much younger women played by Greta Gerwig and Elle Fanning, to enrich her son’s life.

It’s a thoroughly impressive and thought-provoking film with a warm but not saccharine heart that addresses the impact of societal changes such as feminism on women in the late 1970s and now. Despite this sweep, as the actor, a mother of four, explains, the inspiration was more personal.

“Mike started to make this film following his investigations of his own mother,” she says. “But it was actually an investigation of all the women in his life. He interviewed his sister, who is very much like the Greta Gerwig character in the film, but he also talked to friends of his mother and others around him.

“He’s a very empathetic person, but also very incisive – he sees and calls out bullshit. He doesn’t just have this rosy picture of everything; I think that’s what’s so satisfying for us as women watching this picture – it’s not just about watching strong, fabulous women, it’s about watching real women.”

Bening also felt attracted to the project because she had first-hand experience of the atmosphere and setting of the film.

“I’d never read anything like it,” she says. “My impression was very strong right away, partly because I had a real personal connection to the area and the era. I was a young woman in California at that time so the whole milieu that the story was placed in really spoke to me on a personal level.

“In 1979 I was 20 and had just moved from San Diego to San Francisco. I was going to San Francisco State University as a theatre major. It was a time of such tumultuous change in San Francisco – these were the days of Harvey Milk [American’s first openly gay politician, who was assassinated in 1978] and George Muscone [the city mayor, also assassinated in 1978].

“For Mike what we see in the film is a portrait of the artist as a young man. When I moved to San Fran everyone was coming out to be what they wanted to be. It was a time of incredible growth in the economy, in social interaction.

“But he was careful to place Dorothea in that World War Two generation. She’s not hip or a hippy – she’s very uncomfortable with a lot of the changes she sees happening in her son’s generation. I liked that she doesn’t always react as we the modern audience would want her to.”

At one point in the film Gerwig’s character asks: “Do you need a man to raise a man?” and this difficult and still very relevant social and philosophical question is explored, though Mills never loses sight of the authenticity of the characters he creates.

So, what does Bening think? Do you need a man to raise a man? This is perhaps a particularly poignant question since her son Stephen, 25, was born female, identifying as male at the age of 14.

She thinks carefully before answering. “I love that line. And it’s interesting that my character quickly answers ‘No, I don’t think so’. I guess the answer is there is no one way to raise a child. The way we are raised is based on all sorts of things – are our parents still together, what other people come into your life.”

“At my age, I really see the influence of these other adults and mentors. I had great parents and I love my parents very much, but other people also had a huge role.”

Bening was born in Kansas, but moved to San Diego in southern California with her musician mother and salesman father at the age of seven. She talks with affection about the “dear friend” 17 years her senior who lived in the neighbourhood and inspired her.

“When we met I was 12 or 13 and her babysitter,” she smiles. “She was in her early thirties and going through a divorce. By the time I was 16 we were good friends. She was going through her second childhood – single again with two lovely kids, living in suburban San Diego. We did a lot of things together like learning how to scuba dive – we had crazy adventures.

“She eventually got married again, became a teacher and eventually a school principal and now she lives in Oregon. She’s an incredible human being and has always inspired me in the way she lived her life, how she brought up her children, how she embraced adventure. She is still that way now despite her age. I think it’s the real people in your life that inspire you most.”

By the time she made her film debut in The Great Outdoors in 1988, Bening already had a successful theatre career. She met Beatty, her second husband, on the set of Bugsy, and spent the 1990s building a career as a serious actor with a gift for comedy, as seen in films such as Tim Burton’s Mars Attacks!

Looking back, she says, her Oscar-nominated turn in American Beauty, Bond director Sam Mendes’s first film, exploring the emptiness and disappointment at the heart of the American dream, was a significant moment.

“That was a very important role for me,” she explains. “As an actor you are interpreting what is there, of course, but the screenplay was just so good. I was very fortunate to be in that, especially since it’s a film that people still watch and love. But even at the time so many young people were watching it and being impacted by it. I remember I was in a park with my children and this kid on bike, aged about 12, came up and said: ‘Hey, lady! You were in American Beauty – I sneaked into the movies to see that film four times.’ That was such a great moment. This kid wanted to see it over and over again because there was something in it that he related to – that’s very powerful.”

Bening is well aware that many female actors in their forties, fifties and sixties struggle to find good parts, but she acknowledges her own experience has been different.

“I can’t complain so I don’t,” she explains. “I know it is a big issue. We need to see women’s stories on the screen and the people in the business need to understand how much people want to see women’s stories. I also work in the theatre and I choose not to work all the time. I’m very fortunate that I’ve been able to find projects that are completely captivating to me.

“But Hollywood – whatever that means – is driven by profit. It’s showbusiness. Some people are able to make things that are more artistic within that but it’s ultimately about the dollar. It’s also about people’s perceptions of what is commercial – once in a while something breaks through and people are reminded that there are different ways to make a profit.

“There’s no question that the studio system is now involved in huge profitable movies, many of them franchises. There is less interest from the studios in smaller investments that will bring a smaller profit. That’s the part that’s disappointing – what about financing movies that are five, eight, 10 or even 20 million dollar movies? You’ll still make a profit. But there’s great material elsewhere too, so much good TV you can’t keep up with it, from the US, the UK and Europe.”

We discuss how different the world felt in 1979, the year 20th Century Women is set. Eventually, we get on to the digital generation and the significant economic, social and political challenges they face in the coming years.

“My gut feeling is that it is harder for young people now, things really have changed profoundly,” Bening adds with a sigh. “And the amount of information available to people all the time is a really tough thing to negotiate. The younger generation wouldn’t say that – they are good at moving through media and deciding what they want to look at. But for women especially there’s so many added expectations now.

“It will be very interesting to see what sort of art and culture this generation make of all that. But I am genuinely optimistic. I see my kids and their friends and they are all so interested in creating things and responding to everything around them – a lot of good comes from the information age, too.”

She ends on an optimistic note.

“A lot of films this year are actually reminding us of some of the good things about America, and we mustn’t forget those things,” says Bening. “We need to fire people’s imaginations with those good things.”

Amen to that.