As Americans celebrate Independence Day, what does it mean to be a patriot?

Tom Nelson has a cross tattooed on one arm, a deer on the other, a .38 special pistol tucked under his seat, and a commemorative license plate on his pickup truck that reads “Maine Patriot.”

He mulls over how to explain the slogan.

“Well, I pay my taxes. I vote. I follow the law,” he begins. “I support the Constitution. I support the Second Amendment. I’m all for religion, freedom. I support the military, raise my kids right, and take care of my mother.”

For many, that might be a pretty good definition. Others might pick at it. For as much as “patriotism” blooms in the national debate, there is little agreement on what it is. Or who owns it. Or who is a patriot.

As an increasingly riven country chooses up tribal sides, patriotism is being used as a litmus test, but Americans can’t agree on what color passes. National Football League (NFL) players who knelt during the national anthem were accused of not being patriots. They insist their protest was exactly what patriotism requires.

Politicians, especially on the national level, find they cannot run for office without wearing a lapel pin of the flag boasting of their patriotism – Barack Obama had to defend his occasional choice to go pinless during his first presidential campaign. Park statues are torn down – or defended – and streets and buildings renamed in disputes over which patriotic symbols should represent the United States.

Some Americans remain firm in their certainty of what – or who – is patriotic. But in a smattering of conversations around the country, others admit they struggle with the issue.

In Clifton, Ariz., a small copper mining town carved into rock mountains, Steve Guzzo and Bob Jackson say patriotism was woven into expectations of their town, and that sent them both to Vietnam.

“We all come from military families. Most people were World War I, World War II ...,” Mr. Guzzo says. “You were an American, so you paid your dues just like everybody else. You went into the service.”

“I don’t know what [patriotism] means anymore,” Mr. Jackson says. “There’s people that wave the flag and all that. I don’t agree with them at all, you know. But they still have their right to do it.”

The uproar over the decision by San Francisco quarterback Colin Kaepernick to kneel in protest over police brutality and injustice during the national anthem brought a collision of racial grievances and passions about patriotism. Black Americans found themselves, as they have often in history, at a crossroads.

“This current debate really does leave out the experiences and the complex meanings of patriotism for African-Americans,” says Chad Williams, chair of the department of African and Afro-American studies at Brandeis University in Waltham, Mass., and author of “Torchbearers of Democracy: African American Soldiers in the World War I Era.”

“I think African-Americans have historically embraced a type of patriotism, one that is not blatantly white supremacist, one that is encompassing of all that America should stand for: freedom, democracy, equality,” he says.

But the US has long been fractured over who “Americans” should be, from the stirring “all men are created equal” vow of the Declaration of Independence, made hollow by slavery, to the “Give me your tired, your poor” invitation of Lady Liberty now mocked by mass roundups of immigrants.

An American flag stands in the corner of James Bonds’s office in Worcester, Mass., a city 40 miles west of Boston. Mr. Bonds and two colleagues are there. They all served during or just before the Vietnam War. They say they are patriotic, all proud to be Americans. But not proud of all Americans.

“I love this country,” says Nick Schuyler. “You have opportunities here. But the color barriers ...” His voice trails off.

In 2000, there were three Veterans of Foreign Wars posts in Worcester. The men say they inquired about joining, but “the quartermaster never seemed to be there with the right membership form for us to fill out,” says Bonds. He and his comrades are black. The VFWs were all white, he says, and mostly vets from World War II. So the three men started their own VFW post. The other posts eventually closed.

“I definitely support the flag,” says Bonds. “But also realize the flag was used in the South Boston bus riots. Remember the picture of the guy that got beat with an American flag? That’s patriotism? It depends on who is defending it, who is naming it.”

“Protesting is as American as breathing,” says Melvin Collins. “That’s what this country was founded on, Boston Tea Party and all. And keep in mind, if you stifle protests, you are going to end up with something much worse.”

***

All manner of groups have embraced patriotism, for diverse reasons. NFL team owners were paid by the military for years to stage patriotic halftime ceremonies and thunderous jet flyovers, and the owners cultivated the fans who applauded. Country music singers have a repertoire of patriotic songs that are foot-stomping staples of rural county fairs and star-studded tours.

Preachers have woven patriotic threads into their sermons, presuming God has chosen sides. The political parties offer up vows of patriotism. Conservatives have staked a louder claim to the term; some say patriotism has been appropriated by Southern white men.

Even some companies find advantage in the symbolism: Jeep, Levi Strauss, Coca-Cola, and Disney usually top the annual  “most patriotic brands” survey by Brand Keys, a New York marketing consulting firm.

Much of this might seem the amusing backwash of a raucous democracy, but competing claims of patriotism are helping wedge America apart. Measured by polls, hate crimes, and inflammatory rhetoric, the country is becoming more polarized than it has been in at least 50 years, when Vietnam and civil rights ripped at the social fabric.

Surveys paint a somber picture. The proportion of Americans who say they are “extremely proud” or “very proud” to be Americans declined to a record low of 75 percent in March 2017, from its post-9/11 high of more than 90 percent, according to Gallup. Tolerance for other people’s views plummeted along with it.

Trenton Whitehead runs a tax preparation business in Theodore, Ala. Orderly rows of military portraits hang on his office wall. The top row is reserved for his two sons and his niece, while his clients’ family members who served in the military fill the other rows.

Patriotism means America first, Mr. Whitehead says. It’s the unshakable love of country, even if you disagree with Washington politics. Whitehead says he is tolerant, even of the “tree-hugging liberals” ruining the country. The NFL players’ political protest angers him so much that he has stopped watching their games.

“I put my life on the line to defend their right to protest,” says Whitehead, who served in the peacetime army from 1986 to 1990. “They make millions to play a game, and then they want to stand there and tell you life isn’t fair.”

The Gallup polls found a 25 percentage-point gap between Republicans and Democrats on the question of national pride, the largest partisan gap Gallup has found since it began measuring in 2001. Soured by President Trump’s administration, fewer Democrats reported pride in their country than at any time in the past 16 years; Republicans remained high on Trump and on patriotism.

“I’ve always felt that I’m very patriotic, but it’s hard to feel proud of the country right now,” says Cindy Casterline, a retired nurse in Skowhegan, Maine. “Do you see those little children in cages?” she asks of immigrant children removed from their parents. “I can’t live with that.”

***

Patriotism is not always tinder for argument. It can be the necessary glue keeping a country together, especially in times of national threat. Aside from benefits to the country, though, social philosopher John Kleinig argues in “The Ethics of Patriotism: A Debate” that patriotism may be just as essential to individuals as to the country.

The concepts of patriotism become “part of the identity we acquire and for which we develop loyal obligations,” he writes. “It is important for our identity.”

Summers are studded with opportunities to honor those obligations: Memorial Day, Flag Day, Independence Day, Labor Day. For many, these are occasions to reflect, to gather with neighbors, to honor the good aspects of the country.

Dover, Mass., is close enough to Boston to be a suburb, but the community of 6,000 has a small-town, New England feel to it. Houses spread at the end of long tree-lined driveways. The demographic is affluent and white. About 120 residents fill folding metal chairs for Memorial Day speeches.

Robert and Kristy Dixon sit on the grass in the shade waiting for the ceremonies to begin. They describe Dover as “a very patriotic town.” Mr. Dixon points to the town cemetery, a bucolic shady knoll, neatly kept, with flags and flowers by the tombstones of veterans of every war stretching back to the Revolution.

“For everyone who thinks there’s no cost to freedom, they should walk through that cemetery,” says Dixon.

Michael Lesser, who lives in the next town over, came to Dover to see his daughter play oboe for the Memorial Day ceremony as part of the high school band. He is uncomfortable with the flag-waving displays of patriotism.

“I feel that I’m proud to be an American, but I want to feel that it’s understood. I shouldn’t have to fly the flag to prove it,” Mr. Lesser says. “I think in some sense, a flying flag suggests you are more conservative, even jingoistic, than who you really are. You can be proud to be an American but not agree with all of its policies.”

Patriotism is enmeshed with politics, and politics is a national sport. But it is one to be engaged in warily in small communities, where offenses are often long remembered.

“ ‘Don’t talk politics’ is one of three rules you have here,” says Lindsay Corson, a vision of tattooed artistry behind the bar at the South Side Tavern in Skowhegan. “It starts too many arguments.” The other two rules? “No arm wrestling. No throwing [anything].” That seemed evident, Ms. Corson suggested in a shrug.

“Even in this town it’s a mixed bag,” adds a customer, Jason Bessey, who works in the Hannaford food market. “Some people think patriotism is not criticizing our country. But patriotism like that can be bad. Look at Nazi Germany as a dark extreme. If you can’t even criticize your country, that’s a very bad place.”

Down the street, Karen Dore hustles home from her job on the housekeeping staff of Maine General Hospital. At 5:30 every afternoon she opens the door to her garage, which has been converted into a store. An eagle-bedecked sign in the yard advertises Freedom Firearms.

“It’s for the freedom to bear arms, the freedoms of the Constitution,” says Ms. Dore, still in her hospital scrubs as customers come through the door. A woman with a baby in her car plunks down a stack of $20 bills owed on a gun purchase. Ken Gordon wanders in to pick up a Colt .45-caliber revolver, a gun he recalls fondly from his 21 years in the Army.

Mr. Gordon dawdles to consider the issue of patriotism and protesting football players. “It’s just disrespectful of our country,” says Gordon. “But I respect their right to do it.”

Dore is more pointed. “I don’t think they should. I’m one of those with my hand on my heart.”

“The flag, patriotism, the Second Amendment ... it’s all mixed together,” says Dore.

***

Views of patriotism generally fall into two camps, says Peter Dreier, a professor of politics at Occidental College and author of “The 100 Greatest Americans of the 20th Century: A Social Justice Hall of Fame.”

“The first is ‘my country, right or wrong,’ ” he says by phone from Los Angeles. “The other is, ‘my country, love it and fix it.’ The latter view is that my country has a set of ideals and a patriot is someone who tries to move the country toward the ideals.”

Dr. Dreier notes that many of those closely identified with the symbols of patriotism embraced the second definition. The words to “America the Beautiful” were written by Katharine Lee Bates, an ardent feminist and lesbian who protested US imperialism in the Philippines, according to Dreier.

A sort of unofficial national anthem, Woody Guthrie’s “This Land Is Your Land,” penned in 1940, has this little-noticed but damning stanza: “In the shadow of the steeple I saw my people/ By the relief office I seen my people/ As they stood there hungry, I stood there asking/ Is this land made for you and me?”

Even the author of the Pledge of Allegiance, Francis Bellamy, “was a socialist who believed the country was suffering from rampant greed of the robber barons, the gilded age, the exploitation of immigrants, and the sweat shops, the slums, the racism,” Dreier says. “He thought the country could do better.”

The founders of the country were not particularly tolerant on the issue of patriotism. In the lead-up to the American Revolution and during the war, most of the new states passed “test acts” requiring all men to swear an oath of allegiance to the new union and forswear Great Britain, according to John Alexander, professor emeritus of history at the University of Cincinnati and author of “Samuel Adams: The Life of an American Revolutionary.”

These were harsh laws, Dr. Alexander says, and violators faced being stripped of legal rights or even being executed. They were designed to force the hand of a reluctant citizenry, most of whom “wanted to stay neutral,” he says. “They wanted to be left alone.”

Gradually, loyalty to a national government grew. By the Civil War, soldiers were jostling to bear their side’s respective flag on the battlefield, even though flag-bearers were often the first ones shot, according to Alexander.

Support for every war has been frothed by calls of patriotism. Stirring appeals helped usher the US into the Spanish-American War, rallied volunteers to the slaughters of World War I, and – reignited by Pearl Harbor – produced long lines at enlistment offices for World War II.

And cries of “un-patriotic” squelched dissent to wars. Aviator Charles Lindbergh went from national hero to the object of murmurs of treason for his resistance to World War II. In the white-hot passions over Vietnam, police and National Guardsmen beat and sometimes shot those protesting the country’s policies, who were seen by many as ungrateful and un-American. Cars sprouted bumper stickers that rejected dissent: “America – Love it or Leave it.” Presidential candidate George Wallace used his speeches to denigrate and threaten hecklers, singling them out as unpatriotic in a manner later mimicked by candidate Donald Trump.

Indeed, patriotism was such a useful cloak for suppressing dissent that, early on, it earned its own cynical description: “Patriotism is the last refuge of a scoundrel,” said Englishman Samuel Johnson in 1775. The dictionary author looked scornfully at the American rebels, observing dryly that “the loudest yelps” for American liberty came from slave owners.

***

Yet while patriotism has remained a volatile issue in the country, some traditions surrounding it have withered and changed hue. Cadets from the North Quincy High School junior ROTC assemble in a parking lot across from a falafel shop for the Memorial Day parade in Quincy, Mass., eight miles south of Boston. They wear sharp blue uniforms and twirl fake rifles. There are nearly 120 of them. All but a handful are of Asian descent, reflecting the town’s demographic shifts.

Paul Moody shows up with a sun-yellow Ranger pickup truck festooned with American flags. He is commander of the Sons of The American Legion Morrissette Post. He remembers when the Memorial Day parade in Quincy was a big deal. “I think the politics hurt that. Vietnam was a political war. Afghanistan and Iraq were political. So the vets aren’t honored the way they should be.”

Fire engines, police motorcycles, marching veterans, and school bands wind their way to the Mount Wollaston Cemetery. The kids are then dismissed and melt away, leaving a small crowd of mostly older citizens gathered around a podium to hear town officials. After the speeches about sacrifice and valor, after the expectable reading of “In Flanders Field” and the unexpectedly soaring rendition of “The Star-Spangled Banner” by four teenagers from the high school choir, after the gun salute and taps, Robert Noble, age 92, moves resolutely with a walker toward his car.

He is dapper in a tie and coat, with a World War II pin on one lapel and another pin to commemorate prisoners of war. He was one. After the invasion of Normandy on D-Day, Mr. Noble’s unit made it almost to the German border where he was captured and held as a POW for four months, until the war ended.

He is sanguine about public patriotism. “A lot of it depends on what is happening in the country,” he muses. “There are times when veterans are particularly appreciated, and other times they are not.” He has no bitterness about that. “I just feel very fortunate to be here.”

The following week, in a makeshift federal courtroom in the heart of Boston, a crowd sits expectant and a little nervous. The big room is full. “Look at everyone here,” whispers Suma Omara. “Everyone is happy.”

Ms. Omara, a small woman in a burgundy headscarf, is from Egypt. To her right, Mirlande Jean-Baptiste, from Haiti, wears a wildly floral dress, scarlet lipstick, and dangling earrings. To her left, Canadian Barbara Curran laughs at her new friend’s observation. All would become US citizens this afternoon, taking an oath in Boston’s Faneuil Hall, a stately building that once hosted the treasonous exhortations of Samuel Adams to dump English tea in the harbor.

US District Court Judge Mark Wolf applauds the diversity of the 351 aspiring citizens before him, coming from 72 countries. But he admits that not all arms are open to them. “Some of you have experienced difficulties or discrimination because you appear to be different,” he says.

Outside Faneuil Hall, new citizen Yasameen al-Mharib acknowledges the reality of ambivalence – even hostility – toward Arab immigrants. But she notes, tellingly, “my first right is to vote.”

She fled Iraq eight years ago, lived as a refugee in Syria for six years, and now has a college degree from the Wentworth Institute of Technology in Boston and works as a computer engineer. She emerges from Faneuil Hall with her citizenship certificate and gets a hug from her high school friend, Sura Alazzawi, who also fled Baghdad, escaping to Syria then Turkey before joining her pal in Boston.

“A lot of people here supported me,” Ms. al-Mharib says. “They said I was welcome here.”

Carmen Sisson in Alabama and Jessica Mendoza in Arizona contributed to this report.