PORTLAND, Maine — From City Hall to the State House to the White House, elected representatives and the people they represent are engaging in an escalating war of words.

But a Portland campaign is trying to turn down the noisy rhetoric, while dialing up the level of “civility” in public discourse.

Choose Civility Portland is hosting a forum on Wednesday where residents can discuss the opportunities and barriers to becoming part of the Portland community. The facilitated discussion, “Welcoming: Energizing Community Connections,” is free to the public, and is scheduled from 4 to 6 p.m. at the Portland Public Library, 5 Monument Square.

Choose Civility Portland is modeled after an initiative by the Howard County, Md., public library system to foster “respect, consideration, empathy and tolerance” in the community. Since its founding in 2007, the national grassroots education campaign has spread from Maryland to Minnesota, Miami and now, Maine.

Backed with a $50,000 grant from The Lerner Foundation, Choose Civility Portland has also created a 100-book collection at the library, led a public workshop on writing letters to newspaper editors and sponsored film screenings, lectures and other events designed to improve public conduct.

Civility means manners, but Choose Civility is not just about etiquette lessons.

“To maintain a level of openness and inclusion in our community, we have to have some level of civility,” said Kimberly Simmons, the library’s Choose Civility coordinator. Civility calls for respecting others and their opinions, she explained, even if they’re unpopular.

“Civility is about being able to tolerate difference,” Simmons said. “Unfortunately, we live in an intellectually segregated time, in which we often don’t have a place to hash out community issues. We become less connected from a sense of common good.”

That’s a theme echoed by events in Portland, where City Hall has been the site of public discussions that have sometimes turned acrimonious.

In recent months, Mayor Michael Brennan has had to gavel down protesters who have shouted and interrupted City Council meetings. In September, a woman was arrested in council chambers after she refused to sit down during a discussion of the pending sale of Congress Square Plaza. And on Monday, Congress Street resident Janet Daigle — a frequent critic of the city’s Public Services Department — once again stood in the chambers and accused city officials of being “liars.”

The vitriol extends to Augusta, where Gov. Paul LePage has become internationally infamous for his offensive public remarks.

In the oft-quoted words of Rodney King, the California man whose police beating incited the 1992 Los Angeles riots, “Can’t we all just get along?”

Perhaps not, says Daniel Shea, director of Colby College’s Goldfarb Center for Public Affairs and Civic Engagement in Waterville.

“We no longer understand, appreciate or like the other side in politics,” Shea said. “What we’re seeing is a slow, steady, increase in nastiness.”

Shea, who delivered a Choose Civility public lecture in September, has conducted national surveys about the tone of American politics for the past three years. Sixty percent of the public believes the country is “headed in the wrong direction” because of the vitriol among politicians, pundits and the press, he said.

And 50 percent of Americans believe there has been a decline in the tone of politics since 2008, according to Shea’s research.

“Elected officials used to be able to do their thing, with their own special interests, but at the end of the day they’d still find a compromise,” he said. “Today, it’s getting harder and harder for them to even sit in the same room.”

The reasons are many, he said. They include the increasing partisanship of political parties, the growth of extremist news outlets and social media, and even the popularity of TV reality shows.

“Reality TV is really nasty stuff. The best scenes are when people are yelling at each other,” Shea said, and the public’s affection for that sort of entertainment spills over into politics.

Shea believes the tide of incivility can be reversed, but it will take time.

“We can move toward civility in politics, but it will likely be a slow, grassroots, middle-class effort,” he said. “There are many pieces involved, and I don’t see a quick fix.”

Ultimately, however, the effort will be worthwhile.

“The ability to sit and listen to a differing opinion is at the core of our policy processes,” Shea said. “Being respectful to the other side is a democratic value.”