Should NFL Players Express Political Views During the Game?

Suppose there were an anti-abortion NFL player. For him, abortion is killing innocents. So each time a touchdown is scored, he unfurls a sign that reads “Abortion is Murder!”

Is that OK?

The Dallas Cheerleaders display a sign during the national anthem , “Women earn 70% of what men earn in equivalent jobs!”

Is that OK?

Trump supporting players and Trump opposed players put on baseball caps expressing their particular political views while seated on the bench.

OK?