The problem is the hangup with the commerce clause. Catalog companies didn't threaten to make a significant % of all sales into postal sales, the internet does. I'd hope that we could find a way to straighten things out where the state can still assess the sales tax the way it's written legally without bringing all of these other issues about affiliates into it.
I don't really see where states can go on this, the current strategy seems to be "try and force congressional or SC action", good luck with that. Maybe they just fold on sales tax altogether and shift that burden to income tax.