President Trump holds up a New England Patriots jersey during an event honoring the Super Bowl champions at the White House on April 19, 2017.Joshua Roberts / Reuters

It’s hard to imagine Major League Baseball inviting President Trump to throw out a ceremonial first pitch before any World Series games next month. And he definitely won’t be tossing the coin before the Super Bowl next February. Over the weekend, Trump ignited a firestorm in the sports world by harshly criticizing the NFL for failing to punish players who take a knee during “The Star-Spangled Banner.” Then he withdrew his invitation to Stephen Curry of the NBA champion Golden State Warriors to visit the White House because Curry was “hesitating” about accepting the invitation. Curry’s teammates subsequently announced that none of them would go to the White House but instead would use the team’s February trip to Washington to “celebrate equality, diversity, and inclusion.” On Saturday night, an Oakland A’s catcher Bruce Maxwell became the first MLB player to take a knee during the anthem. On Sunday morning, Trump was back at it, calling on fans to boycott NFL games.

Trump’s comments are the precise opposite of Franklin Roosevelt’s famous Green Light Letter to baseball owners in 1942, urging them to keep the game going to boost the nation’s morale during the Second World War: “These players are a definite recreational asset to at least 20,000,000 of their fellow citizens.” On Friday, Trump offered a Red Light: “Get that son of a bitch off the field right now. Out. He’s fired. He’s FIRED!”

Pro sports have long found patriotism to be good for business. Field-sized flags and taxpayer-funded flyovers are de rigueur for big games. Presidential complicity has been an important part of that arrangement. Presidents since Taft have been lobbing ceremonial first pitches. George W. Bush famously threw out the first pitch of the 2001 World Series, the first after 9/11, wearing a bulletproof vest. The first World Series champion to visit the White House was the 1924 Washington Senators. In recent years, practically every team that’s won a major championship, college or pro, has been invited to meet with the president.

The choreography of the champions-visiting-the-White-House dance had been perfected. The team presents the president with a personalized version of its jersey, usually with his name and the number of his presidency emblazoned on the back. (“Michelle Obama Throws Out a Bunch of Barack’s Old Number 44 Jerseys,” The Onion joked last fall.) The president holds it up, smiles broadly, cracks a few jokes. It was, by most measures, a harmless and mutually beneficial arrangement: The teams and their leagues got good publicity. The president got to bask in the reflected glory of champions.

The presidential-sports complex was perhaps the last fully functioning bipartisan tradition left in Washington. This weekend, Trump blew it up. His short presidency has been marked by many watersheds. But this one feels different. If the president is at war with pro sports, no cow is sacred anymore. Trump v. Sports promises to be a long-running drama.

Of course, Trump’s comments were about race as much as sports. Nearly all the athletes who drew his ire—the anthem kneelers and Steph Curry—are black. The Uppity Negro Athlete is a familiar trope in white America, and one that resonates especially with Trump’s supporters. Playing in the NFL (which is 70 percent black) is, in Trump’s opinion, a “privilege.” Never mind that it’s a privilege that comes with dreadful risks, including the degenerative brain disease CTE.

Black athletes who take a knee are “disrespecting our Flag & Country” and should be fired or suspended, Trump wrote. Here, sadly, Trump stands more closely aligned with historical precedents. After Tommie Smith and John Carlos gave the Black Power salute on the medal stand at the 1968 Summer Olympics in Mexico City, Lyndon Johnson refused to invite the U.S. track and field team to the White House. (Obama finally invited Smith and Carlos to the White House in 2016.)

It’s also worth noting Trump’s short, miserable record as the owner of the New Jersey Generals, a United States Football League team. Trump urged his fellow USFL owners to sue the NFL, with disastrous results. Although the NFL was found to be in violation of antitrust laws, the USFL was awarded just three dollars in damages. Perhaps the president still harbors ill will from this embarrassing episode.

Something else Trump said at his rally in Alabama Friday night is getting less attention, but is historically significant in its own right. “The NFL ratings are down massively,” he said. “Because you know today if you hit too hard: 15 yards! Throw him out of the game! They had that last week. I watched for a couple of minutes. Two guys, just really, beautiful tackle. Boom, 15 yards!” Trump, in his scattered way, appeared to be referring to recent rule changes that prohibit blows to the head and protect defenseless pass receivers from dangerous hits. What Trump is lamenting, of course, is what he perceives to be the feminization of pro football. (His supporters sometimes call it “pussification.”)

As a historian and a sports fan, I was reminded by Trump’s comments of one of his predecessors, Theodore Roosevelt. President Roosevelt also believed in “rough games and in rough, manly sports.” But in 1905, troubled by a rash of injuries and even deaths on the gridiron, he ordered the nation’s college presidents to clean up the game or risk having it banned altogether. As a result, dangerous mass formations were banned and the forward pass was legalized. The game was made safer—and more fun to watch.

Trump, whose only exercise appears to be golf (though, to be fair, he plays a lot of it), wants to undo the precedents of his predecessors. He wants make football less safe, its players less diverse, and its celebrations thoroughly partisan. FDR wrote that sports should go on, even in a time of war, because Americans “ought to have a chance for recreation and for taking their minds of their work” and their troubles. Trump’s comments this weekend have taken that refuge away.

We want to hear what you think. Submit a letter to the editor or write to letters@theatlantic.com.