The President of the United States is a uniter.

He has unified football, basketball and baseball players; coaches, management and athletes; protesters and conservative NFL owners.

He has prompted players to kneel, raise fists and link arms, and their employers to defend them.

He has turned American professional sports, for so long an old boys’ club united only by a hatred of taxes and a willingness to cloak itself in patriotic symbolism, into an awkward bastion of peaceful protests.

The First Amendment had itself a day on Sunday.

What Colin Kaepernick began with a knee, Donald Trump accelerated with a speech.

This weekend, the man who destroyed the USFL said, “Wouldn’t you love to see one of these NFL owners, when somebody disrespects our flag, to say, ‘Get that son of a bitch off the field right now.’ Out. He’s fired.”

Trump’s words produced an NFL Sunday unlike any other.

Before the Vikings beat Tampa Bay, 34-17, at U.S. Bank Stadium, Viking players, management and owners linked arms, and most of the Buccaneers players did the same. A few of the Bucs knelt.

The Bucs’ gesture was meant to defy Trump and continue Kaepernick’s protest. Vikings players said they were expressing solidarity. They could have done more, especially knowing what one of their own endured.

In 2014, Vikings defensive tackle Tom Johnson was Tasered and pepper sprayed by two Minneapolis police officers who said he ignored warnings to leave a downtown restaurant at closing time. A jury acquitted him in 15 minutes. He is suing the department for using excessive force.

“Everybody knows what’s going on and how the president feels,” Johnson said. “We want to be unified. We’re riding together. We respect one another. We just wanted to do something to make a statement.

“Even if I didn’t have my own situation, I would still feel this way. I’m from the South. I understand. I’ve experienced things myself.”

Most Vikings weren’t willing to call the issue by name, but they should. We’re talking about racism. That’s what Kaepernick was protesting, not the flag, the national anthem or American soldiers.

While white athletes have rested hands on shoulders or offered encouraging words, all but one of the male professional athletes who have conducted on-field protests have been black, and have been protesting unjustified and unpunished killings of black people.

Across the NFL on Sunday, teams and players chose different forms of protest. Some teams stayed in their lockerrooms during the anthem. Some players knelt or sat. Giants receiver Odell Beckham, Jr., caught a touchdown pass and raised his fist.

On Saturday, the A’s Bruce Maxwell became the first baseball player to kneel in protest, and this weekend Warriors coach Steve Kerr said: “They’re not protesting the flag. They’re protesting police profiling and killing black people with impunity. Is that not worth protesting?”

LeBron James called Trump a “bum” on Twitter. Bills kicker Steven Hauschka said in an interview with the Buffalo News, “It’s important for white people to see there is inequality everywhere.”

This weekend, perhaps more than any other, has made sticking to sports impossible.

That’s always been a dubious idea. Sport often reflects and sometimes improves society. Jesse Owens and Jackie Robinson did more to destroy racial stereotypes than a million well-intentioned speeches.

And sport has invited politics to the party. Many NFL owners donated to Trump’s campaign, and Trump made Jets owner Woody Johnson an ambassador to Great Britain. Flyovers and flag unveilings at games are intended to align the NFL with the U.S. military, to paint the league as patriotic whether or not the league deserves that description.

Before the game on Sunday, the Vikings released a tepid statement. After the game, most players remained stubbornly vague. It’s always strange when the physically strongest people in our society act fearful of meaningful words.

They could have simply handed out a quote that reflects the United States Constitution.

“Peaceful protests are a hallmark of our democracy. Even if I don’t always agree, I recognize the rights of people to express their views.”

Martin Luther King? John F. Kennedy?

No. Those words were tweeted on Jan. 22 by Donald Trump.