Racing star Dale Earnhardt Jr. defies NASCAR owners to show solidarity with NFL protesters

Racing legend Dale Earnhardt Jr. is apparently not on board with NASCAR owners' threats to drivers to not take part in protests against police brutality that take place during the national anthem.

On Twitter Monday morning, Earnhardt Jr. expressed his support for the right of all Americans to engage in nonviolent protests -- and he shared a quote from John F. Kennedy in which he said that, "those who make peaceful revolution impossible will make violent revolution inevitable."

Over the weekend, multiple NASCAR owners said they would fire drivers who took a knee during the national anthem, and Trump on Monday tweeted out his approval of their threatened crackdown on protests.

"'So proud of NASCAR and its supporters and fans," the president wrote. "They won’t put up with disrespecting our Country or our Flag – they said it loud and clear!"

Trump has now been attacking NFL players for kneeling during the national anthem for four straight days. His campaign against NFL players' peaceful protest began on Friday night, when he called NFL protesters "sons of b*tches" during a campaign rally in Alabama.