The president had, once again, misrepresented the situation. The players are not, as a whole, protesting the national anthem. (There are bodies in the street, Kaepernick had said.) They are not protesting the flag. They are protesting police brutality against African Americans. They are protesting the lack of legal accountability for the officers who enact that violence. They are protesting, more broadly, the ways racism gets codified in America, the ways it is expanded from a personal evil into a societal one.
That was the issue when it was only about half a dozen or so taking a knee a week ago. However, the 200 or so who took a knee yesterday were protesting Donald Trump and what he said.