Washington governor Jay Inslee wants to require out-of-staters to pay sales tax on any purchases they make, but if they pay $25 or more, they can fill out some paperwork and get their money back. He's banking on the idea that most people won't bother, and so their nickels and dimes can then remain in the state's general fund.
Presently, non-residents don't have to pay sales tax on non-consumables if they display a state identification card such as a drivers license, although they do have to pay at, say, restaurants. Inslee wants to change that up by throwing some paperwork and postage into the mix.
Some Oregonians and Idahoans may be mildly inconvenienced, though most of us won't be.