It was an implicit dig at NFL players who have protested during the playing of the national anthem, and it added one more note to a surreal back-and-forth over what is usually a lighthearted and apolitical ceremonial duty. It came near the end of a day's worth of sharp-edged criticism from the White House that added fuel to the running conflict between Trump and NFL players, and supporters of each — and the broader cultural battles central to much of the president's political appeal.