TRUMP IS CORRECT: NFL teams can legally fire players for their conduct.

And Greg Jarrett is also correct:

Don’t expect NFL owners to do the right thing by firing players. They’ve been coddling them for years, paying lavish salaries and tolerating misbehavior that is now endemic in football. Along the way, owners have become rich beyond imagination. The players run the teams, not the owners.

But we the people have the final say - with our wallets. Enough wallet closures and they'll begin to pay attention.