Washington DC - When JD Vance's memoir Hillbilly Elegy was published in 2016, the book was widely cited as a key insight into understanding how America elected Donald Trump as president that year.

Now, the Republican presidential candidate has chosen the author as his running mate, thrusting the bestseller back into the spotlight.

As soon as Vance was announced on the Trump ticket, the book rocketed to the top of Amazon's list of bestselling books in the US.

Its publisher, HarperCollins, began reprinting the book, which has already sold over three million copies in the eight years since it first hit shelves, according to the New York Times.

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In roughly 270 pages, Vance recounts his youth growing up in rural America that is reeling from a declining economy and loss of hope.

Raised by grandparents from Kentucky, Vance illustrates how a historically Democratic electorate of Appalachia grew to support Trump in the face of shrinking steel, coal, and agriculture industries.

It tells Vance's life story as a boy who is born into poverty but rises to the heights of Yale Law School, one of the most elite educational institutions in the country.

When the memoir came out, Vance was just a 31-year-old financier working in Silicon Valley.

The book, which was later adapted into a film on Netflix, launched Vance into the national spotlight.

He used his success to pivot to a career in politics – he was elected to the Senate from Ohio in 2022 and now is in the running for the second-highest office in the US.

Four days after Trump won the presidential election in November 2016, the New York Times published a list of six books "to help understand the victory" of political outsider Trump over Hillary Clinton.

Hillbilly Elegy was among them, "a compassionate, discerning sociological analysis of the white underclass that has helped drive... the ascent of Donald J. Trump," read its review.

Vance grew up in Middletown, Ohio, a steel town that "has been hemorrhaging jobs and hope" for as long as he could remember, he wrote in the book.

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He was taken in by his grandparents instead of being raised by his drug-addicted mother and describes the community he grew up in as having "a culture that increasingly encourages social decay instead of counteracting it."

At the same time, Vance says he loves this community and uses a pejorative nickname for them, "hillbilly," in the title of his book as a way to fight the stigma. This characterization, however, drew controversy, as several critics accused Vance of reducing the Appalachian people to brutal stereotypes.

Some left-leaning writers said the people that Vance described were not responsible for their own decline but were instead victims of a system that left them impoverished.

The book also illustrates a radical shift in Vance's views on immigration and foreign trade.

Today, he speaks of a need "to protect American industries from all of the competition" and says the cheap labor of undocumented immigrants is destroying American jobs.

But in the memoir, he posited that Americans should not blame the economic policies of Barack Obama or China for their problems, but look themselves in the mirror.

"We talk about the value of hard work but tell ourselves that the reason we're not working is some perceived unfairness: Obama shut down the coal mines, or all the jobs went to the Chinese," Vance wrote. "These are the lies we tell ourselves."