Delta is a private company so if they want to ban someone they can. He can fly another airline.
How I’ve handled my airline issues...
I’ve refused to fly for over twenty years.
Most trips I can get there faster by driving.
I save a bleepload of money.
I never lose my luggage or have to sit with my knees under my chin.
Delta et al can KMA.
Bake the cake! They are open,to the public- that was the aru,ent used agaisnt sweet cakes business when they wouldn’t bake the cake for a gay wedding.