Why the Washington state income tax is unconstitutional
Washington’s constitution has long treated income as property—and that classification comes with strict limits. Property taxes in Washington must meet two clear requirements: they must be uniform, meaning the same type of property is taxed at the same rate, and they cannot exceed a 1% cap.
The proposed state income tax violates both.
First, it applies only to certain individuals—those earning above $1 million—while exempting others entirely. That is not uniform taxation. Second, the rate itself is far beyond the constitutional limit, reaching roughly 10%, which is ten times higher than what is allowed for property.
Supporters argue the policy targets only high earners, but the legal issue isn’t who is taxed—it’s how. Under the constitution, income as property must be treated consistently and within strict boundaries.
The constitution can be amended, of course, but that requires a vote of the people. Washington voters have rejected an income tax the last ten times they’ve been given the choice. This time, proponents avoided that process—rejecting amendments that would have allowed voters to weigh in directly.