Retired Milton S Herring saluting US flag, Los Angeles National Cemetery Annual Memorial Event, California. (Photo By: Visions of America/UIG via Getty Images)

Of course, a divided America can't agree on the definition of patriotism

Updated 10:16 AM ET, Wed November 8, 2017

(CNN)We think we know patriotism when we see it.

A veteran in uniform, saluting a July Fourth parade. Elementary school students angled toward the flag, reciting the Pledge of Allegiance. A line of professional athletes, standing at attention during "The Star-Spangled Banner."
But when one of those athletes kneels, it gets complicated.
At stadiums around the country this Sunday, some NFL players will take a knee during the National Anthem as part of ongoing demonstrations against racial injustice and recent comments by President Donald Trump. Some fans will boo, as they booed 49ers quarterback Colin Kaepernick last year when he launched this form of protest.
And on Twitter, many will demonize the players as unpatriotic.
But what does that mean, exactly? The dictionary definition -- a "love for or devotion to one's country" -- doesn't quite cover it.
It's possible to love your country and still, like a parent scolding a wayward child, speak up when you feel like it's gotten off track. Just like it's possible to serve in the military and grow disillusioned with the government whose uniform you don.
Veterans recite the Pledge during a Memorial Day ceremony at the Golden Gate National Cemetery in San Bruno, California.
Americans are sharply divided. In a CNN poll, 46% say protesting during the anthem is disrespectful to the freedoms the anthem represents. An almost equal 45% say such protests demonstrate those freedoms.
Patriotism comes in many forms. And in 2017, when anything can and will be politicized, it's not so easy to define.

Patriotism is passion

Patriotism seems especially fervent among two groups of Americans.
The first, of course, is veterans and their families. For many, patriotism is attendant to military service, and dying in combat is the ultimate sacrifice anyone can make for their country.
Thus, for many military families, showing disrespect for the flag, the National Anthem or other American symbols can come as a slap in the face.
"I stand for our flag and anthem, and I kneel for our fallen. That's what patriots do," said Keith Harman, a Vietnam combat veteran who leads the 1.7 million-member Veterans of Foreign Wars of the United States. "We rally around the flag of our country, not use it and our Constitution as both shield and sword."
Honoring the US military has become part of the pageantry of NFL games, from jet flyovers to enormous American flags unfurled on playing fields. Indeed, the Pentagon has spent millions of dollars on "paid patriotism" displays at sporting events, a 2015 report found.
People wave flags on September 11, 2017, along an overpass near Melvern, Kansas.
But some wonder whether other groups of Americans should also be afforded the same kind of tributes.
"Wrapping yourself in the flag and honoring the military is something which no one is going to object to. We all respect their sacrifice. We all honor their sacrifice," sportscaster Bob Costas told CNN this week. "And yet what it has come to mean is that the flag is primarily and only about the military.
"This is no disrespect to the military. It's a huge part of the narrative. But Martin Luther King was a patriot. Susan B. Anthony was a patriot. Dissidents are patriots. Schoolteachers and social workers are patriots."
Also often welling with patriotism are immigrants.
Many of these newcomers fled poverty, violence or oppression in their native countries, and so they have special appreciation for the freedoms other Americans might take for granted.
Immigrants take the Oath during a naturalization ceremony on September 15 in New Jersey.
Just go to a naturalization ceremony, where eyes well with tears as oaths of allegiance are sworn by newly minted US citizens.
"I'm very excited," Ahmed El-Mallah told CNN at one such ceremony in New Jersey in February, five years after he arrived from Egypt. "I'm very lucky to be here today."

Patriotism is partisan

It used to be simpler. During World War II, we were all patriots. Decades later, we swelled with national pride when our country somehow landed two men on the moon.
And in the tender weeks after September 11, 2001, we bonded through our shared anger and grief. We flew flags, sang "God Bless America" and vowed to defend our way of life -- rock 'n' roll, fast food and all -- against all enemies. When pollsters asked Americans last year to name the time in their lives when they felt most proud of their country, the top answer was during the national response to 9/11.
But that spirit waned as our country's political climate grew more partisan, fueled by echo chambers in the media and on the Internet. And a "patriotism gap" grew between our major political parties.
A man pauses on September 11, 2015, at the Ohio Statehouse lawn in Columbus to memorialize victims of the 9/11 attacks.
Gallup polls revealed that Democrats were consistently less likely than Republicans to feel "extremely" or "very" proud to be Americans.
When Barack Obama became a presidential candidate in 2007, many questioned his muted expressions of patriotism. That October, Obama took heat after a reporter in Iowa noticed he wasn't wearing an American flag lapel pin. "I'm less concerned about what you're wearing on your lapel than what's in your heart," Obama said then. But by the time he accepted the Democratic nomination in August 2008, a flag pin adorned his suit jacket.
Last week, President Donald Trump inserted himself into the debate when he said the NFL protests are a "total disrespect of our heritage, a total disrespect of everything that we stand for."
"If a player wants the privilege of making millions of dollars in the NFL, or other leagues, he or she should not be allowed to disrespect our Great American Flag (or Country) and should stand for the National Anthem," he tweeted. "If not, YOU'RE FIRED. Find something else to do!"
President Donald Trump speaks on September 22 at a rally in Alabama.