Kneeling in protest during the national anthem began with former San Francisco 49er Colin Kaepernick in 2016, but the act has expanded beyond the football player, including rapidly catching on over the weekend.

Athletes on football teams across the country knelt Sunday in protest after President Trump called for the firing of athletes who choose to protest during the national anthem. NBA players entered the conversation when Golden State Warrior Stephen Curry said he had no interest in visiting Trump at the White House, citing the president's language as part of the motivation behind his absence. Bruce Maxwell, a catcher for the Oakland Athletics baseball team, knelt before their game. WNBA teams opened their championship series Sunday, and they also responded to the president's words. The Los Angeles Sparks remained in their locker room, and the Minnesota Lynx locked arms during the anthem.

But one sport in which you probably won't see much participation in the protests is NASCAR.  Professional auto racing is the only sport Trump singled out on his Twitter feed as responding appropriately to his words about protests.

NASCAR was among the many businesses and organizations that cut ties with Trump after the June 2015 campaign launch in which he called Mexicans “rapists,” among other things. The league canceled a banquet scheduled to be held at Trump National Miami Doral resort in response to those remarks.

But NASCAR chief executive Brian France was solidly on board with Trump's politics nearly a year later when he came out publicly for Trump during the 2016 presidential election, calling the political neophyte a “winner.” France faced major blowback from sponsors after his endorsement.

France has not yet responded to Trump's latest remarks, but other prominent voices in the pro auto racing community have — and most of them were anti-protest. NASCAR itself issued a statement, saying, “Our respect for the national anthem has always been a hallmark of our pre-race events.”

Team owner and former driver Richard Childress implied Sunday that any of his employees that participated in protests during the national anthem would be unemployed.

“Get you a ride on a Greyhound bus when the national anthem is over,” he told a local Fox affiliate when asked what he would do if one of his employees protested during the anthem. “I told them anyone who works for me should respect the country we live in. So many people ... gave their lives for it. This is America.”

Racing legend and team owner Richard Petty said any athlete participating in protests should have to leave the United States.

“Anybody that don’t stand up for that ought to be out of the country. Period,” he told the Associated Press. “If they don’t appreciate where they’re at … what got them where they’re at? The United States.”

Andy Murstein, co-owner of Richard Petty Motorsports, said he'd tell protesters that their action is “the wrong thing to do.”

“I would sit down with them and say it's the wrong thing to do that, and many people, including myself, view it as an affront to our great country,” Murstein told ESPN. “If there is disenchantment towards the president or a few bad law enforcement officers, don't have it cross over to all that is still good and right about our country.”

And Trump took to social media to praise the NASCAR community for its support.

“So proud of Nascar and its supporters and fans. They won't put up with disrespecting our Country or our Flag - they said it loud and clear,” he tweeted Monday.

It wasn't surprising that the professional auto racing community generally came out in support of Trump, especially when you review its demographics. NASCAR fans lean conservative, and polls show there's a clear partisan divide in how conservatives and liberals view race and protest in America.

According to The Washington Post-UMass Lowell poll, 64 percent of professional auto racing fans come from the South and the Midwest, regions that Trump carried in the 2016 election. And supporters of the sport tend to be older “and fall well outside the 18- to 34-year-old demographic coveted by advertisers,” SB Nation reports. Trump carried older voters in the 2016 election.

These things matter in part because although some critics have said athletes should stick to politics, sports have become part of the culture wars — and Trump understands that, which is probably in part why he targeted activist professional football players during a rally in conservative stronghold Alabama.

Not everyone affiliated with NASCAR agreed with Trump.

Driver and team owner Dale Earnhardt Jr. tweeted a quote from former president John F. Kennedy about what censoring peaceful protests could do to a democracy.

“All Americans R granted rights 2 peaceful protests. Those who make peaceful revolution impossible will make violent revolution inevitable-JFK,” Earnardt tweeted.

NASCAR itself has made efforts in recent years to reach out to minorities, which was part of the reason for the blowback against France's 2016 endorsement. Despite the warm reception to his profane assessment by many fans, it would be wise for Trump not to rely too heavily on support from the NASCAR community. For all of Trump's jabs at the NFL's declining ratings, the number of people tuning in to watch NASCAR is declining, as well.