The political dialogue in America has grown so abrasive and malicious that it can pit friends and family members against each other. When we air our self-righteous opinions on Facebook or in conversation, we may set up invisible barriers between ourselves and some of our closest acquaintances. Perhaps we share the same political ideals as our friends, but what about our in-laws, neighbors and coworkers?

Author Ethan Casey is trying to get behind those barriers as he works on his next book, “Home Free: An American Road Trip.” Casey is traveling around the country and talking to people of varied backgrounds to break through the political rhetoric and collect stories from real Americans to find out where the country is headed.

“We have very bitter, divisive politics that, especially in the last few years, have had Americans of different factions and persuasions really at each other’s throats,” Casey said. “I’m trying to take a step back from that stuff, and at the same time jump with both feet into the deep end of American society.”

A Wisconsin native now living in Seattle, Casey’s road trip will bring him to the Seacoast for an event at Portsmouth Public Library on Thursday, Oct. 11. He’ll offer a presentation about his travels before sitting down to chat with locals about the stories and issues on their minds.

Casey is an international journalist who has written for numerous publications, including the Boston Globe, and has covered Thailand, Cambodia, Nepal, Zimbabwe, Haiti, Pakistan and other countries. He has previously written books about Haiti and Pakistan, including 2010’s “Overtaken by Events: A Pakistan Road Trip.”

“The gist of those projects is to humanize the experience of ordinary people, to re-contextualize public events in terms of the priorities and worries of ordinary Pakistanis and Haitians,” he said.

“I think we need to look at our own country in the same way. We Americans, I think, are all too often in the habit of politicizing everything, and our national conversation tends to be all around the politics and less about what the point of the politics is in the first place.”

Casey’s American road trip began in September and will continue in a clockwise loop around the nation through December. But applying the same approach to his home country as he did to Haiti and Pakistan won’t be easy. Here, the issues hit closer to home, especially in his native Wisconsin, which he visited last month.

Over the last couple of years, Wisconsin has become a model of political acrimony. Republican Gov. Todd Walker (who recently visited New Hampshire in support of Mitt Romney) has become a figure of national controversy for his efforts to strip the collective bargaining rights of labor unions. Casey said he spoke to a woman at a bookstore in his hometown who said she now avoids talking politics altogether.

“Especially because all the feelings have been so raw in Wisconsin in particular over the last couple of years, she flinches from talking about political issues, because somebody might just jump down her throat, or she might find herself jumping down somebody’s throat,” Casey said. “I think that’s a really telling analogue for what I think is happening all over the country.” 

Based on Casey’s observations, political tensions tend to be most pronounced in big cities, where “people’s political attitudes are part of the baggage of who they are,” he said. On the other hand, he spoke to a farmer in rural Wisconsin who lives in harmony with his wife, even though they have opposite views of Gov. Walker.

“He said, ‘I tell ya, my wife’s a school teacher and she hates Walker, but I think what he’s doing is just fine,’” Casey said. “What struck me and really was moving and maybe a little surprising is that you’ve got this division of views within a family, and I think there are many, many families like that all over America.”

Casey spoke to the director of the Republican Party in Waukesha County, the most conservative region of Wisconsin. He also spoke to Occupy protesters who are against Walker’s agenda. He’ll incorporate his conversations with people around the state into the first chapter of his book, due out in 2013.

“I’m going to try to stitch that together into a mosaic portrait of Wisconsin as a representative American place,” he said.

From there, Casey is traveling to Cincinnati to stay with a Tea Party supporter and evangelical Christian. Then he’ll swing through Detroit before coming to New England, where he’ll visit a married gay couple in Massachusetts. Later he’ll go to Miami to talk to the Haitian immigrant community. Then he’ll move west across the country to southern California before making his way up the Pacific Coast.

By the time he returns to his starting point in Seattle around Christmas, Casey hopes to have spoken with a broad range of people affected by different political issues that have stirred up national controversy in recent years.

“I take the politics and put it in the background and the reporting I do is in the foreground, the humdrum daily experience and the life stories of ordinary people, and I trust that the political context or the topical context will be there and it will also bubble back up into the reader’s awareness,” he said.

Already, Casey has come to some uncomfortable realizations about his country. Although we tend to think America has little in common with third-world countries like Haiti and Pakistan, our problems are essentially the same, he said.

“One thing I feel I’ve learned is that America is affected by all the same forces that affect any society,” Casey said. “It’s not any less susceptible to authoritarian politics or ... economic crises.”

Casey does not know what he’ll learn on his American road trip. One of the challenges he faces is to leave his own political ideals at the door when he meets people and listen without prejudice, but to do it without presuming that he can remove himself entirely from the issues. “I don’t believe in that ideal of objectivity,” he said.

Casey said it’s too early in his journey to say whether people’s basic concerns are different depending on what part of the country they live in. But he acknowledged his trip may ultimately challenge the notion that we are a unified nation.

“The conclusion might be, wow, this isn’t one country. It might be that there are a lot of ragged edges and schisms and dangling participles all along the way. And that might be part of the story of America that we need to discover,” he said.

The free event at Portsmouth Library is co-sponsored by Seacoast Peace Response and NH Peace Action. Casey will sign copies of his previous three books and present a slideshow before meeting with individuals to talk. It begins at 7 p.m. at 175 Parrott Ave. in Portsmouth. For more information, call 603-427-1540 or visit www.cityofportsmouth.com/library.