On the face of it, John Legend has a lot of positives in his life right now. A preternaturally talented musician, he released his sixth LP Darkness and Light before Christmas and is preparing to take its winning blend of off-kilter, jazz-infused, soulful pop out on the road.

Legend’s involvement with two of the biggest films of recent times – La La Land, in which he co-starred as jazz-popper Keith (not the biggest leap in imagination, casting-wise) and provided the hit song Start a Fire, plus Beauty and the Beast, for which his title track duet with Ariana Grande has been a global smash – was an unqualified success. They follow on the heels of his Oscar in 2015 for Best Original Song for Glory, from the film Selma. And at home, as millions of his Instagram followers will know, he’s the very proud • father of young daughter Luna with his model wife Chrissy Teigen, who has established herself as one of the funniest famous folk on social media.

And yet the softly spoken and unfailingly polite Legend, born plain old John Stephens in Springfield, Ohio, in 1978, is simmering with a quiet fury. The fury is here in the room at Broadcasting House, even as Legend is preparing to be all smiles on The One Show following our interview. And it is most certainly there on his most recent song In America, released as part of the soundtrack to TV series Underground, telling the story of the underground railroad in Georgia during the slavery era, on which Legend is executive producer and appears in the new series as abolitionist leader Frederick Douglass.

“It probably is my most political song to date, yeah,” agrees Legend. “It doesn’t get much more political or angry. The lyrics, ‘I still can’t breathe’, that is referencing what happened in New York with Eric Garner. But also, it was written for a show about slavery. I’m thinking about the parallels between the oppression that black people have endured in America over the years.

“Of course it was at its height during slavery but there are parallels that we’ve seen with the criminal justice system in America now. So when I wrote about what it means to be in America as a black man, I wrote about that contradiction between the ideals of America – that we are free and equal, that we share the American dream – and when we don’t live up to our ideals.”

If it sounds like a call to arms, Legend warning his oppressors that he “won’t stand around” and watch America go down, then that is exactly as he intended.

Legend may seem an unlikely resistance leader. But he has form for protest. Wake Up!, his 2010 LP made in collaboration with The Roots, was a collection of protest songs, with Legend’s usual slick sound punctured by a new, raw soul edge. And this was before Donald Trump’s emergence as a political force saw Legend become increasingly publicly outspoken.

“People are realising now how impactful politics is on our lives,” says Legend, 38. “And when we have a normal, sane president it can kind of slip out of your consciousness because you know you don’t feel like it affects you all the time.

As a kid I would read about civil rights heroes and presidents and sports figures I looked up to

“But now that we have someone who is so unbalanced and unprepared and unqualified, I think a lot of people are realising how important good leadership is and how important it is for us as citizens to use our voices to speak out for issues we believe in, and to vote for the right people to lead us and represent us. A lot of people that weren’t politically engaged are becoming more so. I already was. But I certainly am not going to stand around and watch America go down now.”

So, what sparked Legend’s political education? Like so many before and since, he learned about the figures who inspired him in his local library. Self-taught and home-schooled, Legend sought out giants of the political, activist and sporting worlds.

“My parents used to take me to the library and I would read about civil rights heroes and presidents and sports figures I looked up to,” he says. “I was seven years old but liked to read about leaders and change-makers. I always thought of myself as somebody who was going to be a leader, even as a kid.

“I mean Dr King was a hero, Frederick Douglass, Harriet Tubman, Abraham Lincoln, John F Kennedy. These are all people I was intrigued by. And the more I read, the more I talked to people, the more I realised how much politics actually affects people’s lives.

“It’s not just academic and something to be studied. It has real impact. And when you see that impact, you know how important it is to our health insurance, you know how important it is to make sure kids have the opportunity to go to good schools and live in safe communities, have enough money to put food on the table.

I can speak out for people who may be marginalised and may not get as much attention. But celebrities aren’t going to save us

“All these things are genuinely, practically felt by people every day. And politics affects those things. So what I think about politics, I’m not just thinking about kind of on the ideological level. The debates go back and forth between people who disagree but I’m thinking about, well, how does this affect the citizens? How does it affect the poor? How does it affect the working class? Hopefully our leaders are thinking that too, but sometimes I feel I fear they might not be.”

Legend sees his role in amplifying the message. He knows he has a big audience. He has lambasted Rupert Murdoch and Donald Trump, implored his followers to ring their representatives in the build up to the vote on the abolition of the Affordable Care Act (more commonly known as Obamacare), and is active in championing improved public education, serving as vice chairman of the Harlem Village Academies, which runs several charter schools in New York.

“I can speak up for issues that may be overlooked. I can speak out for people who may be marginalised and may not get as much attention as I would. And we’re all part of the dialogue. But celebrities aren’t going to save us. The people are going to have to, from the ground up, and be involved and speak out and stand up – and it looks like they are. That’s why we still have Obamacare. Because people stood up. So it was good to start with a win.”

But how to balance the public and private? Legend and Teigen appear more comfortable than most to live in the glare of the spotlight.

“I think it is easy for me and for my wife because I feel like we start from an honest place with everything we do. So when we talk about political issues it’s because we actually genuinely care about them and have something to say. I’m comfortable calling out powerful figures. If we feel confident in what we’re saying, we’re not shy about saying it.

“And then when it comes to the family, I think that we’re like a lot of new parents, you know? Most parents post their kids’ pictures on their Facebook. They are excited to be new parents. They are excited for all the different milestones. You watch your kid making you proud and want to share it with your friends. It just so happens that our network of friends is millions of people. So we get a few more likes than some people.”

The white supremacist movement has come out of the shadows. They feel emboldened by Trump’s election

Legend talks of his fears for the future. A future in which the racist underbelly that has always existed in US society is now more powerful and more confident than ever.

“The white supremacist movement has come out of the shadows,” he says. “They feel emboldened by Trump’s election. He made them feel like they can say what they always wanted to say in public but were afraid to say.

“That’s a disturbing trend. And it’s not just the impoliteness of being openly bigoted. But it’s the actual material effects of that. We saw a white terrorist randomly kill a black man in the street in New York the other day. And we’re seeing more people around the country with that level of animus toward black and brown people. And Trump has encouraged it by demonising Muslims and demonising Mexicans. He’s made a lot of people feel like it’s a life and death issue whether or not they accept immigrants, and given that he’s painted – particularly – black people with such a dishonest violent characterisation, he makes a lot of people feel justified in violence toward those people. So he’s actively encouraged people to be violent toward brown people in our country. And it’s very scary and dangerous. Add his misogyny to that and it’s a tough time for a lot of people in America right now.”

As a mainstream pop performer, Legend is sanguine about the likelihood of many of his fans having voted for a president he describes as “embarrassing, irresponsible and dishonest”.

“A lot of people deal with that even in their own families,” he says. “You know you can love someone but not agree with their politics. You still have dinner with them at Christmas and Thanksgiving.

“Some of my fans are choosing to ignore the fact that they disagree with me politically and still enjoy the music. And some people are saying they’re not going to listen to me because they don’t agree with me.

“But I will say that if you are a conservative and you only want to listen to conservative artists and only want to consume the art of conservative creators you might have some slim pickings!”

Darkness and Light is out now. John Legend tours the UK in September; johnlegend.com

John Legend

John Legend: “Politics feels like a calling at the moment”