Don't be so sure about that. The legislature's constituents include a lot of small businesses that have never liked the concept of collecting state taxes when internet companies don't, creating an unfair competition. The small businesses are made up of voters who live in the districts and vote in local elections. The out-of-state internet companies do not.
So who's side do you think the legislators will take?
My point is that if Amazon decides they won't do business in states that tax them or their affiliates they will eventually find themselves with no American business. If they won't do business in Illinois, Texas, New York and California, what are their hopes of long-term profitability?
Who said they aren't "doing business" in Illinois?
You can still go to Amazon.com and they will take your order.
Do you understand what Amazon has done and what the law passed by Illinois does?