A handful of self-proclaimed white nationalists interrupted an appearance by an author at the Politics and Prose bookstore in Northwest Washington on Saturday afternoon, chanted “This land is our land” and then exited to a chorus of loud boos.

The men walked in as author Jonathan M. Metzl, a psychiatrist and director of the Center for Medicine, Health, and Society at Vanderbilt University, was discussing his new book, “Dying of Whiteness: How the Politics of Racial Resentment is Killing America’s Heartland.”

Metzl’s book explores how some lower- and middle-class white Americans are drawn to politicians who promise to improve their lives but who promote policies that place white Americans at greater risk of illness and death. His research found that people in states that rejected Medicaid expansion and blocked the full Affordable Care Act lived shorter lives and states that made it easier to buy guns saw hundreds more firearm deaths.

About 10 white protesters walked into Politics and Prose shortly after Metzl began his talk at 3:30 p.m., videos posted on Twitter show. They gathered in front of Metzl, and an unidentified man with an electric megaphone declared, “You would have the white working class trade their homeland for handouts.”

Amid the booing, the man added, “But we, as nationalists and identitarians, can offer the workers of this country a homeland, their birthright, in addition to health care, good jobs and so forth.” The booing got louder. He then started the chant of “This land is our land,” and the men walked back out.

No one was hurt, and no damage was done to the store, said co-owner Bradley Graham. “The audience was not particularly receptive,” Graham said. “We just let them have their say, expecting they would leave, and they did. It doesn’t often happen here. It’s a sign of the times.”

Metzl said, “It was pretty intense. I think everyone was really surprised. I get lots of threats on voice mail, but this was the first time in person.” He said the group appeared well-organized and had a videographer.

Metzl said that when the protesters walked in, he was talking about a man in the bookstore audience who had helped his father and grandparents escape the Nazis in Austria. “I was saying how much stronger America is when we think about our responsibility to people in need. At that point, the Nazis walked into the talk.”

Metzl added, “It was very symbolic for me. In case anybody’s wondering what’s happening right now, they’re illustrating my point.”