Court battle ignites over Washington's new income tax
Opponents of Washington’s new income tax on high earners filed a lawsuit Thursday, arguing the controversial law is unconstitutional and in conflict with nearly a century of state Supreme Court precedent.
This marks the start of a much-anticipated legal brawl over the law, which Gov. Bob Ferguson signed late last month. Dubbed the “millionaires’ tax” by backers, it imposes a 9.9% tax on household wage earnings above $1 million a year.
“We are challenging an illegal, unconstitutional income tax that clearly flies in the face of the constitution, of precedent and of voter will,” said former state attorney general Rob McKenna, who is running point on the effort to invalidate the law.
The core argument opponents of the tax make is that income is property and, according to the state constitution, property taxes must be applied uniformly and cannot exceed a rate of 1%. This makes graduated or progressive income taxes unconstitutional, they contend.
https://washingtonstatestandard.com/2026/04/08/court-battle-set-to-begin-over-was-new-income-tax/