Alicia Machado became an American citizen just in time to vote against Donald Trump. It’s a vote that has been a long time coming.

In May 1996, the Venezuelan beauty queen was just 19 years old when she was crowned the winner of the Miss Universe pageant, which had recently been bought by the Manhattan business mogul. That year should have been one of sheer happiness and possibility for Machado, and for a moment it was. “I remember I hug my mom and I tell her, now our lives is going to be changed forever,” she told the Guardian in an interview in her adopted hometown of Los Angeles.

Trump attacks Alicia Machado again: 'She gained a massive amount of weight. She was the worst' Read more

But when she put on weight soon after winning, Trump turned what should have been a golden year into the most traumatizing one of her life. It wasn’t just that Trump shamed her about about gaining weight, calling her things like “Miss Piggy” and “an eating machine”. It wasn’t even that he did so publicly. It was that he did it with the biggest audience he could find, in an attempt to sear her weight fluctuation into the public consciousness, forever changing how she would be remembered.

Then on Monday night, in a twist of cosmic justice, Trump – now the Republican nominee for president – was presented with a bigger audience for his comments about Machado’s weight than he ever could have imagined, or wanted.

In what has been billed as the most-watched debate in presidential history, Democratic candidate Hillary Clinton made Trump’s remarks to Machado a centerpiece of their first televised clash, citing the name-calling – in particular, Trump calling her “Miss Housekeeping” in reference to her Latina origins – as a prime example of her opponent’s demeaning views about women.

Trump’s treatment of Machado reached its nadir in January 1997 when, having put the recently crowned Miss Universe on a stringent diet and exercise regime, he scheduled a trip with her to a New York City gym. There he blindsided her with dozens of cameramen, who gathered to film her jumping rope, lifting weights and pedaling a stationary bike. Trump cast himself in the role of disapproving dad, leaning over Machado as she hid her mortification behind a show of charms only the world’s top beauty queen could have mustered, laughing along with reporters and even once planting a kiss on Trump’s cheek.

Facebook Twitter Pinterest Alicia Machado of Venezuela reacts as she is crowned Miss Universe on 17 May 1996. Photograph: Eric Draper/AP

Although she appeared happy, smiling for the crowd of cameras as she dutifully skipped rope, she tells the Guardian she felt like a mouse in a cage, running endlessly on her fixed wheel for the entertainment of others. “I was in some gym in New York like a mouse,” she said. “Look at that mouse: how she run, how she jump, how she make exercise. Like that. In that moment is when … problems come to me and start.”

The media loved the spectacle, and so did Trump, who didn’t hesitate to pass out some memorable if fallacious tidbits himself. “She weighed 118 pounds or 117 pounds and she went up to 170, so this is somebody who likes to eat,” he said in an interview at the time. In fact Machado says she gained only a fraction of that weight but she didn’t dare correct him; she was already frightened he’d make good on a threat to strip her of her crown if she didn’t follow through on the performance at the gym. (Trump’s campaign did not return a request for comment.)

Machado never did lose her crown, but she lost her health for a time. Though she had never suffered from eating disorders previously, in the years that followed the ordeal at the gym, she struggled with anorexia and bulimia. It took five years before she was fully recovered, and longer before she could talk about what she went through. Now she hopes to use the insights gleaned to help teenagers struggling to love their bodies.

“No matter what, no matter who tells you that you don’t look good, that is only outside,” she said, speaking partly, perhaps, to her younger self. “You are more than some weight. You are more than some phase. You are more than if you are short or tall, or you are black or you are white, or you are skinny or fat or whatever. Your value is how you can work, how you can feel for the people around you.”

She added: “In this moment 20 years later, the only thing I need to say is I’m a really happy person. I’m a very successful person. I have my family, my daughter, my career, my dreams, my ideas.” Referring to Trump’s character, she said: “And he can’t be a president of the United States of America.”

That Machado is thriving these days was readily apparent from where she sat in her publicist’s fourth-floor office in West Hollywood, and apparent in many different realms. She has traded pageants for success as an actor, starring in a string of telenovelas – a childhood dream come true. She is also a successful businesswoman, with a line of products bearing her name. And she is the proud mother of a seven-year-old girl, whose privacy she fiercely protects; a question about whether she would encourage her daughter to compete in beauty pageants was met with stern disapproval.

More recently, she has added another title to her list of identities: activist. In June, Machado teamed up with civil rights icon Dolores Huerta in Virginia to join immigrant advocacy groups in encouraging Latinos to register – and to vote for Clinton. She took her own advice to heart, too. On 19 August she became a registered US citizen, pledging in a post on Instagram to cast her ballot for Clinton. Later that month she traveled to Florida to lend her star power to a Clinton campaign drive to register Latino voters, posting video excerpts from the trip to social media accounts.

Her celebrity is at the nexus of two very important voter groups this election cycle, and they are groups overwhelmingly supportive of Clinton: women and Latinos. Both have been broadly insulted by Trump, who has called Mexican immigrants “rapists” and regularly refers to women as animals; Machado has the dubious distinction of being the recipient of both racial and gender-specific slurs, a powerful reference point that certainly isn’t lost on the Clinton campaign.

“Alicia Machado has seen first hand the dangerous impact Trump’s hateful and divisive rhetoric can have on people,” a Clinton spokesperson said of Machado’s involvement with the campaign. “As a Latina, as a first-time voter and as a respected leader in the Latino community, Alicia has become an invaluable voice of our campaign to help mobilize Latinos against Trump’s bigoted agenda and to educate the community about Hillary’s plans to build a better future for them.”

In the first presidential debate on Monday, Machado’s value could scarcely have been more evident. Clinton’s strongest moment in an already impressive debate performance – arguably her strongest moment in the cycle – came near the end when she seized on a question about what Trump had meant when he had said she didn’t “look” presidential. Trump tried to deflect the damaging line of inquiry, saying he had actually been questioning her stamina. Clinton wasn’t having it; and she used the concrete details of Machado’s story to pull him back in the ring of fire.

“He tried to switch from looks to stamina, but this is a man who has called women pigs, slobs, and dogs, and someone who has said, ‘Pregnancy is an inconvenience to employers.’ Who has said, ‘Women don’t deserve equal pay unless they do as good of a job as men,’” Clinton said as Trump tried to protest.

“One of the worst things he said was about a woman in a beauty contest,” Clinton continued. “Her name is Alicia Machado and she has become a US citizen, and you can bet she’s going to vote this November.” It was a rare moment in which Trump’s words were effectively weaponized against him. And, for the first time all debate, Trump had noticeably lost his cool, switching focus to offensive comments he had made about TV personality Rosie O’Donnell and saying: “I think everybody would agree that she deserves it and nobody feels sorry for her.”

Another measure of the attack’s effectiveness came the following morning, when Trump was asked on Fox and Friends what, if anything, from the debate had gotten under his skin. Without hesitation he singled out Machado. “She was the worst we ever had, the worst, the absolute worst. She was impossible,” he said of the former beauty queen.

“She was the winner and she gained a massive amount of weight and it was a problem,” Trump continued. “We had a real problem, not only that, her attitude and we had a real problem with her. Hillary went back into the years and found the girl and talked about her like she was Mother Teresa and it wasn’t quite that way, but that’s OK.”

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But it isn’t 1996 any more; Machado, far from being a girl, is a 39-year-old woman, and if body-shaming constituted good press for Trump’s fledgling beauty pageant business then, it seems less of a good look for his presidential campaign today. It’s a similar case with his continued insistence on how right he is to call women out for their weight. Machado understands this, perhaps even more acutely than Clinton, because she’s lived it; and she is willing to relive and keep reliving this painful episode if it means shedding light on a man she feels has no business anywhere near the Oval Office.

On a call organized by the Clinton campaign on Tuesday afternoon billed as a chance to let Machado respond to Trump’s most recent attacks, the former beauty queen was much more interested in talking about his Democratic rival, whose mention of her story in the debate the night before had moved her to tears. She “never imagined it would matter to someone so powerful”, she said.

But as someone who straddles two powerful voting blocs this election cycle, Machado is a double threat to Trump, and she feels that her celebrity means she has a responsibility to speak up about her experiences when they can help people. “If I can be a voice for my Latino community in this moment, I will do it,” she told the Guardian.

It’s not just a matter of Trump: a few years ago she survived a battle with breast cancer, and as a person of faith, she said she struggled to make sense of why God sent her such a challenge. Tearing up ever so slightly for the first time in an hour-long interview, she said she finally determined it was because she needed to share her story: “People believe in my words,” she said. “People look at me as a strong person. That is my character – I’m a strong woman.”