As the furor over NFL players taking a knee during the national anthem rekindles, the full power of the players themselves has not yet come into play. Presidential politics and U.S. culture wars combined to make the issue a dominant subplot of the 2017 NFL season. In late May, the league’s team owners reopened the debate by deciding to create a policy requiring players on the field during the playing of the national anthem to stand, under penalty of fines and on-field penalties, though players can also stay in the locker room.