LeBron James called him a "bum," J.K. Rowling cited "privilege" and Stevie Wonder knelt in solidarity at his Saturday concert — Donald Trump's latest feud attacking some of America's best athletes is spilling over into a much wider and deeper confrontation.
The U.S. president continued his condemnation Sunday of athletes on the field taking a knee during The Star Spangled Banner.
"Courageous Patriots have fought and died for our great American Flag," he posted Sunday on Twitter. "We MUST honor and respect it!"
Hours later he tweeted, "Sports fans should never condone players that do not stand proud for their National Anthem or their Country. NFL should change policy!"
Trump's words prompted athletes, entertainers and filmmakers to take a stand — by encouraging others to not stand at all.
"It has nothing to do with football or business," music mogul Sean Diddy Combs wrote Saturday in a tweet directed at athletes. "Ya'll are our stars, you represent us. Ya'll are our strong heroes … show that strength please."
The rallying call — which has been echoed by a number of high-profile voices from actor Samuel L. Jackson to basketball star Stephen Curry — was sparked by the U.S. president's insistence at a public event in Huntsville, Ala., on Friday that those protesting the American flag at games should be "fired."
Quarterback Colin Kaepernick started the kneeling protest in 2016 as a player with the San Francisco 49ers, refusing to stand for The Star-Spangled Banner to put a spotlight on the treatment of black people by police.
Trump's latest criticism has intensified the pushback Sunday from NFL players. Most teams in the early afternoon games locked arms in solidarity. At least three team owners joined their players. More than 100 players sat or knelt as a form of protest.
The Pittsburgh Steelers remained in the locker room as the national anthem played before their game with the Chicago Bears. Coach Mike Tomlin stood by himself on the sideline.
Twenty-seven players from the Jacksonville Jaguars and Baltimore Ravens also took a knee at Wembley Stadium in London on Sunday. Other coaches and players linked arms while standing.
At a Major League Baseball game on Saturday, Oakland Athletics' catcher Bruce Maxwell knelt for the anthem. He's the first MLB player to do so.
The Golden State Warriors say they will not go to the White House when they visit Washington, D.C., early next year. Trump rescinded the traditional invitation in a tweet after Curry indicated he didn't want to come.
The back-and-forth also led James to call the president a "bum" in a tweet, which has since been "liked" more than 1.3 million times. That puts it among the 20 most liked tweets of all time.
Trump reiterated his stance in a tweet early Sunday morning.
The hashtag "take a knee" soon began trending, igniting a heated debate among fans about whether the form of protest is appropriate.
Wonder is among many in the entertainment industry supporting the symbolic action.
On Saturday, the legendary musician was helped to one knee on stage during a concert in New York by his son, Kwame Morris.
"Tonight, I'm taking a knee for America," Wonder told the audience.
Soon after Wonder knelt on stage, he put his other leg down and faced the audience.
"I'm taking both knees," Wonder said. "Both knees in prayer for our planet, our future, our leaders of the world and our globe."
Ugly Betty actress America Ferrera applauded the athletes for "strength and courage," and Olivia Wilde called the sports community "brave."
Selma director Ava DuVernay and comedian and activist Ed Asner also posted messages using #takeaknee.
Rowling and Nanjiani weighed in as well on the battle playing out online.
"Historically, taking on Steph Curry or LeBron separately has resulted in failure," said Silicon Valley and The Big Sick star Nanjiani. "Taking on them together? Well that's just stupid."