Sherman became a fledgling environmentalist and got his revenge after a giant fish kill threatened the livelihood of nearby fishermen. Company officials feigned innocence, but Sherman barged into a public meeting with an incriminating sign: I’M THE ONE WHO DUMPED IT IN THE BAYOU. Fast-forward a couple of decades and Sherman, still an environmentalist, is campaigning for a Tea Party congressman who wants to gut the Environmental Protection Agency. Sherman still distrusts chemical companies, but he distrusts the federal government more, because it spends his tax money on people who “lazed around days and partied at night.”

In “Strangers in Their Own Land,” which has been nominated for a National Book Award, Hochschild calls this the “Great Paradox” — opposition to federal help from people and places that need it — and sets off across Louisiana on an energetic, open-minded quest to understand it.

A distinguished Berkeley sociologist, Hochschild is a woman of the left, but her mission is empathy, not polemics. She takes seriously the Tea Partiers’ complaints that they have become the “strangers” of the title — triply marginalized by flat or falling wages, rapid demographic change, and liberal culture that mocks their faith and patriotism. Her affection for her characters is palpable.

But the resentments she finds are as toxic as the pollutants in the marsh and metastasizing throughout politics. What unites her subjects is the powerful feeling that others are “cutting in line” and that the federal government is supporting people on the dole — “taking money from the workers and giving it to the idle.” Income is flowing up, but the anger points down.

The people who feel this are white. The usurpers they picture are blacks and immigrants. Hochschild takes care not to call anyone racist but concludes that “race is an essential part of this story.” When she asks a small-town mayor to describe his politics, his first two issues — or is it one in his mind? — are welfare and race: “I don’t like the government paying unwed mothers to have a lot of kids, and I don’t go for affirmative action.”