This weekend, the issue of NFL players demonstrating during the national anthem took on renewed significance. President Trump, first in a speech on Friday, and later via Twitter, took aim at the league a few times—targeting the league’s ratings, the rule changes intended to avoid critical brain injuries, and the protests started by former San Francisco quarterback Colin Kaepernick that led NFL players to kneel silently during the anthem, in protest of race-based policing in America.

Trump, speaking in Alabama on behalf of U.S. Senator Luther Strange, opined to the crowd:

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. He’s fired!” You know, some owner is going to do that. He’s going to say, “That guy that disrespects our flag, he’s fired.” And that owner, they don’t know it. They don’t know it. They’ll be the most popular person, for a week. They’ll be the most popular person in this country.

So far, no owner has taken Trump up on his challenge. (Greg Abbott tweeted in August about a fabricated quote from Cowboys owner Jerry Jones, whose actual statements about protests during the anthem have been less strident.) But the NFL reacted on Sunday to the president’s attacks on the league and its players. Commissioner Roger Goodell responded with a statement, as did many NFL team owners—and the players themselves reacted with renewed protest. Almost the entire Oakland Raiders team sat or kneeled during the anthem, and the Pittsburgh Steelers (with the exception of offensive lineman Alejandro Villanueva, an Army vet) remained in the locker room, with head coach Mike Tomlin explaining that he wanted to avoid a situation in which some players demonstrated while others remained standing. The Seattle Seahawks did the same, with a team statement that went even further:

As a team, we have decided we will not participate in the national anthem. We will not stand for the injustice that has plagued people of color in this country. Out of love for our country and in honor of the sacrifices made on our behalf, we unite to oppose those that would deny our most basic freedoms. We remain committed in continuing to work towards equality and justice for all.

Many within the NFL—and the league itself, which cut together an ad in the wake of Trump’s remarks—spent less time addressing the original cause of the protests, which Kaepernick specifically intended as a response to “a country that oppresses black people and people of color,” and more on the broader cause of “unity.” Some teams, including the Houston Texans, demonstrated by having the entire roster link arms, often with the team owner among them, in a demonstration of that unity.

Trump, for his part, decided that he approved of the arm-linking gesture. It should be noted that Patriots quarterback Tom Brady—with whom the president maintains a friendship—participated in that specific demonstration in New England.

Great solidarity for our National Anthem and for our Country. Standing with locked arms is good, kneeling is not acceptable. Bad ratings! — Donald J. Trump (@realDonaldTrump) September 24, 2017

The idea that “kneeling is not acceptable” is curious, though, given its origins. When Kaepernick began protesting the national anthem during the 2016 preseason, he did so by remaining seated on the bench while his teammates stood. The gesture initially went ignored, until a reporter asked him about it; at that point, he expressed that he intended it as a statement about institutional racism in the United States.

AP Photo/Elaine Thompson

Nate Boyer, a Green Beret who played college football at the University of Texas at Austin as a long snapper (and who spent a few 2015 preseason games with the Seahawks), reacted to Kaepernick’s protest by penning an open letter to the quarterback. In the letter, Boyer explained why he was upset at the sight of Kaepernick on the bench during the anthem:

The only time I got to stand on the sideline for the anthem was during my one and only NFL preseason game, against the Denver Broncos. As I ran out of the tunnel with the American flag I could feel myself swelling with pride, and as I stood on the sideline with my hand on my heart as the anthem began, that swelling burst into tears. I thought about how far I’d come and the men I’d fought alongside who didn’t make it back. I thought about those overseas who were risking their lives at that very moment. I selfishly thought about what I had sacrificed to get to where I was, and while I knew I had little to no chance of making the Seahawks’ roster as a 34-year-old rookie, I was trying. That moment meant so much more to me than even playing in the game did, and to be honest, if I had noticed my teammate sitting on the bench, it would have really hurt me.