Long before the ascendancy of Donald Trump, numerous authors, including Thomas Frank (“What’s the Matter With Kansas?”), have probed the question of what drives conservative, working-class voters to resist policies (such as subsidized child care and environmental regulation) by which they stand to benefit.

Five years ago, renowned UC Berkeley sociologist Arlie Russell Hochschild (“The Second Shift,” “The Outsourced Self”), distressed by our increasingly polarized political landscape, became absorbed by the same question.

“But I found one thing missing (from current analyses) — a full understanding of emotion in politics,” she writes in her deeply engaging new book, “Strangers in Their Own Land: Anger and Mourning on the American Right” (The New Press; $27.95).

The result of five years and hundreds of interviews in small-town Louisiana, Hochschild’s book — a finalist for the National Book Award — is her earnest attempt to plumb the emotional roots of Trump supporters’ seemingly paradoxical beliefs. Why, for instance, do voters in one of the country’s most petrochemically polluted regions support abolishing the Environmental Protection Agency?

The subject couldn’t be more timely, and Hochschild explores it with a refreshing lack of condescension. Instead, she shows a deep appreciation for the ways we are all shaped by what she calls a “deep story” of how life is felt, which might ultimately explain more than any poll or pundit ever could. Hochschild spoke recently by phone; the conversation has been edited for length.

Q: What prompted you to undertake such an extended reporting trip to a part of the country that couldn’t be more different, politically and culturally, from Berkeley?

A: Back in 2011, before Trump was on the horizon, I was sensing new levels of acrimony between the right and left, even compared to the political conflict we’ve known in my lifetime. In my Berkeley enclave, I hardly knew any Republicans, and I didn’t know one member of the Tea Party, although 20 percent of Americans agree with their ideas.

I wanted to see what would happen if I found a place that was as far right as my political bubble was left. It turns out that Louisiana is the center of the paradox that I wanted to explore. It’s now the poorest state, and 44 percent of its state budget comes from the government. Yet, by one survey, half of Louisiana voters say they agree with the tenets of the Tea Party.

Q: How did you decide on environmentalism as the keyhole issue you’d focus on?

A: The issues were staring me in the face. Calcasieu Parish is one of the two most polluted counties in the country. I looked around, and the sky wasn’t clear and there was a smell in the air, and yet there is a deep resistance to regulating even the most polluting industries. It’s a quintessential issue, because everybody wants clean air, water and soil. You may say, “Look, I don’t want more Medicaid because I’m not going to use it,” but you can’t say, “I don’t want clean air, I’m not going to breathe it.”

Q: One thing that sets your book apart from other investigations of the left-right divide is your emphasis on the role of emotion in politics. Has it been underestimated?

A: Yes. How people feel shapes their beliefs. I would ask people what politics meant to them, and they’d often answer by telling me what they believed. “I believe in freedom,” or “I believe in family.” Even some broad emotional ideals articulated on both sides of the political divide aren’t necessarily shared. Both left and right value fairness, for example, but they think different things are unfair. Some feel proud of a “give me your tired, your poor, your huddled masses” Statue of Liberty America, while others are proud of a work-your-own-way-up America.

Q: You spent time with people who are listening to Fox News day and night. What role do you think the media has played in furthering this divide?

A: It’s huge. It really can’t be overstated. A few people said they scan other channels, peek at MSNBC, but they feel insulted and denigrated there as bigots and rednecks. They take Fox as the basis of their sense of reality. And they stay there because Fox echoes their feelings of being the forgotten ones.

Q: Journalists and political analysts have been struggling to understand Trump’s rise. What did you learn that sheds light on it?

A: I feel like I spent four years understanding the kindling, and then when I saw Trump at a rally the day before he won the Louisiana primary, I saw the match. I was studying the source of his appeal, not why he was the particular guy that spoke to it. Trump or no Trump, there was a genuinely felt dissatisfaction, and that’s really what the book is about.

Q: You sketch out what you call the Deep Story behind that dissatisfaction, based on the feelings you heard expressed by so many people you interviewed. The story’s central image is of people waiting in a long line for the American dream. Why is it important?

A: In a nutshell, what I heard over and over was a feeling of marginalization — being religious in an increasingly secular culture, white in an increasingly brown society and facing economic uncertainty. And the government is seen as the engine of that marginalization.

We all have a deep story, Tea Party supporters in the South as well as liberals here in the Bay Area. It’s important to try to understand each other’s because often that unspoken story is what comes between us, not sets of facts.

Jessica Zack is a freelance writer. Email: books@sfchronicle.com