As Chimamanda Ngozi Adichie stepped off stage at a conference held in Boston, she issued a call to the thousands of attendees to change the world.

But as she settles down onto a sofa in the catacombs of the conference centre in which she spoke, she’s frank that the call she’s been making for years – through her best-selling books We Should All Be Feminists and Americanah, talks such as this one and her intermittent comments in the press – has become harder lately.

“I think it’s more difficult,” she admits. “Parts of the world that have political power are increasingly moving rightward, and while I think there are some worthwhile ideas on the political right, it’s also on the political right that you have ideas about what kind of person deserves dignity and what kind of person doesn’t.”

Her long, extended speech, delivered from a podium in a cavernous conference hall, touched on the burning injustices that have turned this renowned novelist into a public campaigner.

It was a call for men to treat women with the respect they deserve; for kindness and compassion across the political divide; and for reason above all.

“I think that’s dangerous for the world,” says Adichie about the rightward lurch of our political compass. “Liberal democracy seems to be in trouble.”

Adichie doesn’t think liberal democracy is a perfect system, but believes it’s the best option we have – and that it’s in trouble.

While others grumble about the current state of the world and its perceived spiral into Trump-abetted oblivion, Adichie shouts. (Her outspokenness seemingly causes headaches for her press minders, who repeatedly asked – unsuccessfully – for quote approval as a condition of this interview. Almost every reporter, supposedly, has “misquoted” her in some way.) And she’s unwilling to be silent about Donald Trump’s presidency.

“I think what’s happening in the US now honestly feels like a feudal court,” she says, speaking hours after Donald Trump called an anonymous New York Times op-ed against his presidency treasonous, and hours before one of his aides was sentenced to serve time in a federal prison.

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“For a person like me who grew up in Nigeria, you grew up thinking there are certain countries that generally get things right,” she says. “Certain things can’t possibly happen in the US,” she reasons. “And suddenly you’re seeing that they can. It’s disorienting. I’ve had to accept democracy is a very fragile thing. Disaster can happen anywhere.”

The author-turned-campaigner seems to view America’s 45th president as a catastrophe – not just in the calamitous way he handles the most basic aspects of government, but for his wider impact on political and social discourse as the world’s most powerful man.

An hour earlier, during her keynote speech, she’d called on men to use their intelligence when approaching women; that adults know the difference between romance and predatory behaviour, and to recognise that #MeToo hadn’t brought an end to courting. I ask if she thinks Donald Trump is an adult.

“Clearly he’s not,” she explains. “It’s not a particularly insightful thing to say. I remember saying this fairly early on when he became president. That it felt like Americans had allowed a toddler, had given a toddler the keys to a very expensive and complicated car, and said to the toddler, ‘Okay, you drive.’ That’s what it felt like then, and that’s what it feels like now.”

Adichie thinks that Trump’s ascendancy was a primal reaction to his predecessor. “It’s really not a question of this kind of groundswell of popular support for Trump – it never was. I think the people who voted for him, partly I think it was a reaction to Barack Obama being president. I think people suddenly thought: ‘Goodness: a black man really was president. We’re done with that.’

She underlines the point: “I think there are large parts of this country that are deeply resentful. Some of the resentment is justified,” she adds. “People in some parts of this country feel that they’re looked down upon, that they’re not included. Voting for somebody who’s clearly unstable becomes a way of saying ‘Fuck you’.”

Such a reaction was the result of a fostering, simmering tension spurred on by echo chambers built by technology. “I can’t tell you how happy I am that I can WhatsApp my cousins in my ancestral village, but I think there’s a problem with technology where there’s a need to have categories,” says Adichie. “What is technology doing? It’s narrowing our world view.”

Another catalyst for Trump’s rise was apathy from a large swathe of the US electorate, she reckons. “I know many educated people who did not participate in those elections,” she says. “I think being Nigerian makes it more acute for me, because I think: ‘You actually have a democracy where you can vote and your vote is counted – how can you not?’.”

Yet while the author worries her vision of a changed world – where respect and courtesy are commonplace – has been set back several years, she’s not full of gloom. “I don’t have despair and I’m not positive,” she laughs. “I’m in the middle.

“While I mourn all the ways in which I think America has failed and disappointed me, there’s a sense in me in which I don’t despair, because I’ve seen enough of how this has also propelled people to do things that can remake the world,” she explains.

“Young people are going into politics because of Donald Trump. Women are going into politics because of Donald Trump.” (Days before and just miles from where we speak, a black woman, Ayanna Pressley, became the first African-American woman to be elected to Congress from Massachusetts when she won an upset victory in the Democratic primary.)

“The Democratic party is shifting itself because of Donald Trump,” she says. “I think that’s actually exciting. Even just the idea of misogyny and sexism and women’s rights becoming centre stage is because there’s a misogynist in office.”

In her 2006 novel Half of a Yellow Sun, she recounts the horrors of the Biafran War; seven years later, her novel Americanah looks at race relations in Nigeria, the United States and the United Kingdom. As one of the world’s best social scribes, the present turmoil – Trump, Brexit, and technology’s role in it – appears to all be ripe material for a new book, I suggest.

She tightens up. “I can’t tell you what I’m thinking about, sorry.”

But something is in the pipeline potentially? “I don’t know.” People want it. “I am superstitious and… yeah.”