WA Supreme Court Ruling Could Put New Income Tax at Risk + Sheriff Law Faces Major Court Ruling

A Washington Supreme Court ruling striking down voter-approved Initiative 2066 is raising new questions about whether the court's single-subject reasoning could have consequences for other Washington laws—including the state's newly enacted 9.9% income tax.

The Washington Supreme Court struck down Initiative 2066 in a 6-3 decision, ruling that the voter-approved natural gas measure violated Washington's constitutional single-subject requirement.

I-2066 was approved by Washington voters in 2024 and addressed several policies involving natural gas, utilities, building codes and energy regulations. The Supreme Court majority concluded those provisions represented constitutionally distinct subjects that could not be combined into a single initiative.

Now critics of Washington's new income tax are asking whether the same constitutional reasoning could create problems for Senate Bill 6346.

Washington Policy Center argues SB 6346 contains more than simply a 9.9% income tax on taxable income above the state's $1 million standard deduction. The legislation also includes changes involving the business and occupation tax, sales taxes, the Working Families Tax Credit and funding for early learning.

The Washington Policy Center argues those provisions could create a new single-subject challenge under the reasoning used by the Supreme Court in the I-2066 decision. The Washington Supreme Court has not ruled that SB 6346 violates the single-subject requirement, and the argument remains a legal interpretation advanced by critics of the income tax.

Building Industry Association of Washington Vice President Greg Lane is also warning that the I-2066 decision could have broader implications for laws passed by the Washington Legislature. Lane argues that if the court has established a stricter single-subject standard, that standard must also apply to legislation coming out of Olympia.

The ruling is also raising questions about Initiative 645, the measure asking Washington voters whether they want to repeal the state's newly enacted income tax. Washington Republican Party Chair Jim Walsh says he is concerned the I-2066 precedent could eventually affect how courts review other voter initiatives, including the income tax repeal measure. That is Walsh's concern about the precedent; the Supreme Court has not indicated that it would invalidate I-645.

Also in today's Washington in Focus, the legal battle over Washington's new sheriff qualification law is approaching another ma