There are polls, which say the league has lost attendance and viewers due to such actions, which can therefore be deemed harmful to the league, the team, etc.
He no doubt has a clause in his contracts, stating the consequences of such harmful behavior.
The Owner, GM and head coach should meet with him, and his lawyer, and warn that any demonstration during before, during or after the game will be reason for suspension indefinitely without pay.
Then stick by the warning.
No....it was due to election fatigue....didn't you watch the Fake News to get the right story??