This used to be the case, and Target was exactly one of the companies that made it exactly like this. You'd show your Oregon ID card and the sales tax would be removed (the seller could claim against their sales tax due for a non-resident sale).

However, this was intended to benefit border cities--Vancouver, WA in particular really liked it--but Washington State has no income tax and so is heavily reliant on sales tax. So, as of July 1 2019, the exemption (on state sales tax; local sales tax isn't covered here) may only be claimed post-transaction by the buyer: https://dor.wa.gov/taxes-rates/retail-sales-tax/sales-tax-ex...