Citizen Action Defense Fund: The Case Against the Unconstitutional State Income Tax

Washington’s new income tax may have been signed into law, but the constitutional challenge is just getting started.

Citizen Action Defense Fund has filed a lawsuit challenging the state’s new 9.9% tax on income above $1 million that is led by former Attorney General Rob McKenna and retired Supreme Court Justice Phil Talmadge. Their case centers on a simple argument: Washington’s constitution already provides clear limits on how property can be taxed, and nearly a century of court precedent has consistently held that income is property.

The lawsuit outlines four major reasons why opponents believe the new tax is both misguided and unconstitutional:

⚖️ Income has long been treated as property under Washington law, meaning it is subject to constitutional protections and limitations.

📜 The recently passed tax violates the state’s uniformity requirement by applying different tax rates to different taxpayers rather than treating property equally.

🏛️ The Washington Constitution caps property taxes at 1%, yet the new income tax imposes a rate nearly ten times higher.

🔄 Supporters of an income tax have repeatedly failed to convince voters to amend the State Constitution, raising concerns about whether lawmakers and the governor are attempting to achieve through legislation what voters have consistently rejected at the ballot box.

The case now heads to the courts, where judges will determine whether Washington’s new income tax can survive constitutional scrutiny. The outcome could shape state tax policy for decades to come.

Read the full update from Citizen Action Defense Fund.

At stake is more than a single tax bill—it is whether constitutional limits still mean what they say, even when they stand in the way of some lawmakers’ policy goals.