Colin Kaepernick is used to being under pressure. / Drew Sellers, Sportspress Northwest

As the firestorm builds — not coincidentally in a most cacophonous presidential election year — over QB Colin Kaepernick’s decision to sit for the national anthem before the 49ers-Packers game Friday, let’s all do ourselves a favor and consider this point:

We are historically, politically and socially, a nation of dissenters. It is the thing that keeps us together and tears us apart.

If you can wrap your mind around that screaming incongruity, you’ll be able to take Kaepernick’s awkward but sincere gesture in stride: A law-abiding protest of one designed to provoke the many in a country where dissent is the bedrock agent of change.

From the Mayflower to the first Continental Congress to Abraham Lincoln to Franklin Roosevelt to Brown v. the Board of Education to Rosa Parks to Muhammad Ali to Curt Flood to, yes, Donald Trump, Americans have been — to hijack the immortal expression of esteemed sportswriter Dan Jenkins — a bunch of pisser-offers.

While pisser-offer-ness is hardly unique to America — see the international roll call that includes Nelson Mandela, Mahatma Gandhi and Jesus, among many others — it is the place where it is institutionalized like no other.

My travels to other lands have left me with an overriding impression from non-Americans gazing from afar: They are consistently amazed at how such incorrigible, goofy people get so much done.

Whether it be Normandy, the moon, polio or the internet, contrarian Americans seem to be on the front end of a lot. Back ends too — Good morning, Vietnam! — but we’re not talking about perfection here. We’re talking aspiration and ambition, often at great risk.

I think that was what Vice President Joe Biden was talking about in an interview with the Atlantic that came out over the weekend. Regarding American foreign policy, he said there is a net migration by Mexicans out of the U.S. back to their homeland because it is becoming more stable, thanks in part to U.S. help.

He came up with an amusing analogy.

“Because, guess what? It’s like Ghostbusters, man,” he said. “When there’s a problem anywhere else, call Ghostbusters. We’re Ghostbusters; so it makes sense that we are there to help them because it helps us.”

Biden went on to say that in non-cinematic life, it’s important to pick your fights. But regarding Mexico, Trump wants to build a wall to stop illegal immigration, an idea of profound foolishness, but simplistic enough to trick scared people.

The rest of the world can’t believe we’re even having a presidential-level argument over this. But we are. That’s how we do things. We aren’t any more doomed to the rage of Gozer the Gozerian today than we were in the 1960s, the 1930s or the 1860s.

The movie warned us: Don’t cross the streams.

We always do. We get slimed. We get up.

In my career writing about sports, I’ve always been amused by a ritual in baseball, the most American of our major distractions. The game not only indulges, it celebrates a custom that is not a defined part of the game, yet symbolizes us:

Arguing with the umpire.

We love it when a player or manager challenges authority and risks his continued participation. Confrontation with higher-ups is so in our cultural DNA that we spectators accept this spontaneous theater gleefully. Veracity of the argument is far secondary to the engagement. Other sports have conflicts with officials; none indulge the triple-hat-kick with such triumphalism.

Former Mariners manager Lou Piniella was often embarrassed by replays on stadium video of his legendary tirades, which doesn’t mean he didn’t mean to do them. Given his lesser-known virtues of compassion and responsibility, I’d happily nominate him when the time comes to identify The Ultimate American.

Which gets us back to Kaepernick — not as an Ultimate American, but as a guy upset enough about injustice to put a lot at risk.

As with a baseball manager, he picked a fight he cannot win. It doesn’t matter to him. But his anger is not over safe or out. He’s willing to jeopardize public acceptance, endorsement money and his sports legacy — from now on, he’ll be “that guy” — to take a stand on a matter bigger than him or his team.

Each interception will be met with cackles and taunts of a more cruel variety. Some teammates will suspect he’s distracted. Critics will dismiss Kaepernick as a spoiled, millionaire dumb jock lashing out at a subject he understands only lightly.

I’m not putting him in league with Alexander Hamilton or Martin Luther King here. But I’m thinking he can go a little Norma Rae without getting out over his skis.

In inviting controversy while calling attention to an injustice, he could have calculated better by saying something like, “The courage and sacrifice of our military to protect a right I now exercise humbles me. But their deeds also embolden me to do what I can to move America to a commitment to justice that isn’t merely words on parchment.”

But he didn’t. So the stick-to-sports crowd will have at him, and I get that.

We have constructed the sports industry to be part of the entertainment industry — a haven from reality. But the fact is we have always politicized sports. If you think otherwise, why do the 200-plus member nations of the International Olympic Committee insist on marching into the Opening Ceremony under national flags?

Keeping issues of race, politics and and justice out of the dialogue of sports is no more possible than keeping tide off the beach.

Dissent should be considered America’s 51st state. Pisser-offer-ness needs to be more than an attitude.