I-645 fell short. The constitutional fight against the new income tax continues
Voters did not approve Initiative 645, leaving our state’s new income tax in place. But the election did not settle whether that tax violates the state Constitution.
That question remains before the courts, where former Attorney General Rob McKenna, former state Supreme Court Justice Phil Talmadge, and the Citizen Action Defense Fund (CADF) are challenging the law. Their lawsuit, filed this spring in Klickitat County Superior Court, seeks to invalidate the tax.
There is now a date to watch: February 5, 2027.
According to a post-election update from CADF Executive Director and attorney Jackson Maynard, the court is scheduled to hear a motion for summary judgment, asking a judge to resolve the legal questions without a full trial. Briefing is expected to begin in December.
The February 5th hearing is an important milestone, but it is unlikely to be the final word. A ruling striking down the income tax would almost certainly draw an appeal from the state. The case could then move directly to the State Supreme Court, if the justices accept review. That would mean additional briefing and oral arguments before a final decision. A resolution in 2027 is possible, but no Supreme Court hearing or decision date will be set until after the superior court rules.
The constitutional argument remains straightforward. Washington courts have long treated income as property. The challengers argue that the new 9.9% income tax violates both the Constitution’s requirement that property taxes be uniform and its 1% limit on property taxation.
“For nearly a century, Washington courts have been clear: income is property, and property taxes must be uniform and limited,” McKenna said when the lawsuit was filed in April.
As Future 42 reported earlier this year, McKenna laid out those constitutional objections before lawmakers passed the tax. The lawsuit now asks the courts to enforce those protections.
The November election also helped shape the court that could ultimately decide the case. This week’s latest results show Jaime Michelle Hawk and Sean O’Donnell leading races for two open seats, while sitting Justices Colleen Melody and Theo Angelis will win their races to remain on the court.
Those changes deserve attention, but they do not establish how any justice will rule. Maynard addressed that concern directly in his recent interview, emphasizing that every justice has a responsibility to interpret the law and precedent. He also pointed to the court’s 2023 capital gains tax decision, which upheld that tax without overturning the income-as-property precedent.
Under the current law, the income tax begins January 1, 2028, with the first returns due in April 2029. Those dates will not necessarily impact the timeline for a court decision, however.
For taxpayers in our state, the message is clear: the effort to stop this income tax is still moving forward, and the election results did not change the timeline, nor the strategy.
Read the latest update on the lawsuit and February hearing. Future 42 will continue following the case and keeping you informed as this consequential constitutional fight moves through the courts.