President Donald Trump is once again lashing out at football players who refuse to stand for the national anthem.
Trump claimed on Twitter Friday that "most of them are unable to define" what they're demonstrating against.
Instead, Trump tweets players should "Be happy, be cool!"
Numerous player demonstrations took place during the national anthem at several early NFL preseason games Thursday night, including the Eagles' Malcolm Jenkins. With the support of Chris Long, Jenkins raised his fist during the anthem, as he did last season (see story).
Many other Eagles players made their mission clear with pregame shirts, citing statistics figures on voter registration and percentages of prison populations (see story).
Players have been protesting police killings of black men, social injustice and racism.
Trump writes from his New Jersey golf resort that players "make a fortune doing what they love" and that those who refuse to stand "proudly" for the anthem should be suspended without pay.
Trump has told associates that he believes the anthem issue is a winning one that riles up his base.