Oregon has no sales tax, but an income tax ... so Oregonians get to deduct thier income tax.
Washington has no income tax, but a sales tax ... so Washingtonians get to pay more.
I think the end game is to make it fair ... nobody will get to deduct state taxes.
Actually my personal preference would be to end ALL Federal deductions for state taxes. Let state and local politicians deal with the consequences of their taxation levels.
I guarantee you, all those blue states would start turning red faster than the Pope at a nudie bar.