The Washington Supreme Court Just Fast-Tracked the Income Tax Referendum Case. Here's What It Means.

Published on Apr 9, 2026 — 7 min read

Summary

The Washington Supreme Court just fast-tracked the referendum challenge to the income tax. The case goes to the full court April 30 — and the outcome could put the 9.9% tax on the November ballot.

By Joe Wallin | April 9, 2026 | ~8 min read

Two legal battles are now racing toward the Washington Supreme Court at the same time — and the outcome of each could determine whether Washington's new 9.9% income tax ever takes effect.

The first is the constitutional challenge filed by the Citizen Action Defense Fund, led by former Attorney General Rob McKenna and former Supreme Court Justice Phil Talmadge, which argues the tax is an unconstitutional property tax under nearly a century of Washington precedent.

The second — and the one that just accelerated dramatically — is the referendum fight. On April 7, the Washington Supreme Court agreed to hear Let's Go Washington's emergency petition challenging the Legislature's use of a "necessity clause" to block a public vote on the income tax. The court has fast-tracked the case to its April 30 en banc conference.

If Let's Go Washington wins, they will have until June 10 to collect approximately 154,455 signatures to put the income tax on the November 2026 ballot.

This post breaks down the referendum case: the legal arguments, the constitutional text at issue, the relevant precedent, and what all of this means for tax planning.

What Happened

Governor Ferguson signed ESSB 6346 on March 30, 2026. The bill imposes a 9.9% tax on household income above $1 million, effective January 1, 2028.

Within hours, Brian Heywood — founder of Let's Go Washington — filed a referendum petition with the Secretary of State's office.

The Secretary of State refused to process it.

The reason: the Legislature had inserted a "necessity clause" into ESSB 6346, declaring the tax "necessary for the support of the state government and its existing public institutions." Under the Secretary of State's reading of the Washington Constitution, that language exempts the bill from referendum.

Heywood responded by filing a petition for a writ of mandamus directly with the Washington Supreme Court, asking the court to order the Secretary of State to process the referendum.

On April 7, the court agreed to hear the case on an expedited basis.

The Constitutional Text

The referendum power is established in Article II, Section 1(b) of the Washington Constitution. The key language reads:

The second power reserved by the people is the referendum, and it may be ordered on any act, bill, law, or any part thereof passed by the legislature, except such laws as may be necessary for the immediate preservation of the public peace, health or safety, support of the state government and its existing public institutions.

Read that exception clause carefully. It is a single sentence with a list of items separated by commas. The question is how to parse it — and the answer changes everything.

The Parsing Problem

There are two ways to read the exception:

Reading #1 (Heywood's argument): The word "immediate" modifies the entire list. The exception covers laws necessary for the immediate preservation of public peace, health, safety, and the support of state government. Under this reading, the necessity clause only applies when there is a genuine emergency — an immediate need. A tax that does not take effect for two years cannot plausibly be characterized as immediately necessary for anything.

Reading #2 (Secretary of State's argument): The clause contains two independent exceptions separated by a comma. The first covers laws necessary for the "immediate preservation of the public peace, health or safety." The second covers laws necessary for the "support of the state government and its existing public institutions." Under this reading, the word "immediate" only modifies "public peace, health or safety" — and any law that supports state government is exempt from referendum, regardless of urgency.

What the Case Law Says

Unfortunately for Heywood, Reading #2 has significant case law behind it.

In State ex rel. Blakeslee v. Clausen (1915), the Washington Supreme Court held that "the word 'immediate' qualifies the words 'public peace, health or safety' and no more." This is a direct statement that "immediate" does not reach the "support of the state government" clause.

In Hoppe v. Meyers (1961), the court unanimously reaffirmed this interpretation, treating the two clauses as independent alternatives.

And in Case v. Howell (1915), the court held that a law providing for the support of the state government is exempt from referendum even if the Legislature makes no declaration of emergency.

The effect of this line of cases is that any law whose bona fide purpose is the financial support of the state government — whether through appropriations, raising revenue, or protecting funds in the treasury — is exempt from referendum without any showing of immediacy.

But It's Not That Simple

The case law may favor the Secretary of State's position, but there are real counterarguments — and the court's willingness to fast-track the case suggests at least some justices think the question is worth revisiting.

The structural argument. If any revenue-raising measure is automatically exempt from referendum, then the Legislature can shield virtually any tax from public vote simply by declaring it supports state government. That interpretation would effectively eliminate the referendum power for fiscal legislation — a result that seems inconsistent with the constitutional framers' intent to reserve meaningful check-and-balance power to the people.

The modern context argument. When Blakeslee was decided in 1915, Washington's state budget was a fraction of what it is today. The idea that "support of the state government" meant something narrower — genuine fiscal emergencies, not routine revenue policy — has intuitive appeal in an era when the state's general fund exceeds $70 billion per biennium.

The textual argument. Heywood's team argues that the commas in the constitutional text create a single list, not two independent clauses. Under standard grammatical rules, the phrase reads: laws necessary for the immediate preservation of [A, B, C, or D]. The word "immediate" applies to the entire series. This is a plausible reading — but it runs directly into 111 years of contrary precedent.

The Timeline

Here is where things stand:

April 10, 2026: Secretary of State's response to the petition is due.
April 14, 2026: Let's Go Washington's reply is due.
April 30, 2026: The full court considers the petition at its en banc conference.
June 10, 2026: Deadline to submit approximately 154,455 valid signatures if the referendum is allowed to proceed.
November 2026: General Election ballot (if signatures are collected in time).

The math is tight. If the court rules in Heywood's favor at the April 30 conference, Let's Go Washington would have roughly 40 days to collect over 154,000 signatures. That is aggressive but not impossible — Heywood's organization collected over 400,000 signatures for its 2024 initiative campaigns.

The Two-Front War

It is important to understand that the referendum fight and the constitutional challenge are separate proceedings with different legal questions and different timelines.

The referendum asks: Can the people vote to repeal the income tax? This is a procedural question about the Legislature's use of the necessity clause.

The constitutional challenge (CADF v. State) asks: Is the income tax itself unconstitutional under Article VII of the Washington Constitution? This is a substantive question about whether a graduated income tax violates the uniformity clause.

Both can proceed simultaneously. Both could succeed. Both could fail. And the outcomes interact in important ways:

If the referendum succeeds and voters repeal the tax, the constitutional challenge may become moot.
If the constitutional challenge succeeds and the court strikes down the tax, the referendum becomes moot.
If the referendum fails (either in court or at the ballot box) and the constitutional challenge also fails, the tax takes effect in 2028.
If the referendum proceeds but voters uphold the tax, the constitutional challenge is still live.

What This Means for Tax Planning

The referendum case adds a new layer of uncertainty to an already uncertain landscape. Here is how I am thinking about it:

Plan as if the tax will take effect. The constitutional challenge and the referendum both face long odds. The case law on the necessity clause favors the Secretary of State. The case law on the excise-vs.-property-tax question is murkier after Quinn v. State (2023), but the Legislature clearly drafted ESSB 6346 with Quinn in mind. The safest planning assumption remains that the 9.9% tax will be in force on January 1, 2028.

But build in optionality. If there is a meaningful chance the tax gets repealed — by referendum, by court order, or by future legislation — then you do not want to make irreversible decisions prematurely. Changing your domicile to another state, for example, is a major life decision. If you are on the fence, the next six months will provide significant clarity. By the end of 2026, you will know whether the referendum made the ballot (and how voters responded), and you will likely have an initial ruling in the constitutional challenge.

Accelerate what you can. Certain planning strategies — Roth conversions, exercising stock options, recognizing gain before 2028 — are time-sensitive regardless of the legal outcome. If the tax is struck down or repealed, you have not lost anything by accelerating. If the tax survives, you will be glad you acted early.

Watch the April 30 conference. The court's ruling on the referendum petition will be a significant signal — not just for the referendum itself, but for how this court views the broader legislative power questions surrounding ESSB 6346. A court that is willing to revisit the necessity clause precedent may also be willing to revisit the excise-tax framework in Quinn. A court that defers to the Legislature on the necessity clause may be more likely to defer on the constitutional question as well.

The Bigger Picture

What makes this moment extraordinary is not just the legal complexity — it is the convergence of multiple high-stakes proceedings, all running on compressed timelines, all aimed at the same law.

Washington has not had this kind of fundamental tax debate since the 1930s. The last time the state seriously considered an income tax, the Supreme Court struck it down in Culliton v. Chase (1933). That precedent held for 90 years. The capital gains tax in Quinn cracked the door open. ESSB 6346 walked through it.

Now the question is whether the courts — or the voters — will push back.

If you are a founder, investor, executive, or high earner in Washington, you are watching this in real time. The decisions you make in the next 18 months — about entity structure, income timing, domicile, and exit planning — will depend in part on how these cases resolve.

I will continue to cover both proceedings as they develop. If you want to discuss how this affects your specific situation, book a free introductory call.

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