The reality is that, in these situations, it's more embarrassing to the NBA, and not worth it to keep him. When you have the players talking about boycotting, Civil Rights groups talking about picketing, and advertisers fleeing, that's not good for business. The NBA will find a way to get rid of him, even if they have to kick in some money to sweeten the deal.
I worked for a publicly traded company that did business with Marge Schott, and we did everything we could to sever ties (and our contract). You can't have your brand hurt by people like this. We had PI's following her, we tried to bribe our way of the contract, eventually, we got out. She got a combination of the carrot and the stick. We had pressure from Civil Rights groups, and in general, no one wants to do business with crotchety old bigots.