The slippery slope argument is that first VISA is going after white supremacists. Next they will be refusing to work with any Republican fund raising efforts. It's a dubious argument, but even it were true that this is the direction that VISA is taking, where would this lead?

I don't think VISA will choose to walk away from major customers in the future. More likely, they will continue to turn away the most extreme customers who are also very small.

But if VISA did go down this road, it would open up an opportunity for a new Repulican-oriented credit card company. Or more likely, Republicans would turn more and more to their competitors, such as American Express.