Why the Washington Supreme Court Struck Down I-2066

THE WORLD · SEPTEMBER 22, 2026

On September 17, 2026, the Washington Supreme Court ruled 6-3 that Initiative 2066 — the measure protecting access to natural gas that Washington voters approved in November 2024 — is unconstitutional in its entirety. The case is Climate Solutions v. State of Washington, and the court's holding is narrower and more specific than "the initiative is gone": the majority found I-2066 violates a single clause of the state constitution, article II, section 19, which bars a law from covering more than one subject, and that because the parts raising separate subjects can't be cleanly separated from the rest, the whole measure falls together. The ruling has already become a flashpoint in this fall's Washington Supreme Court elections, with campaigns pointing to it to argue for or against specific candidates — which makes it worth being precise about what the court actually said, what the initiative actually did, and which of the justices who ruled are actually on this November's ballot.

What I-2066 Actually Did

I-2066 was drafted by a coalition led by the Building Industry Association of Washington and placed on the ballot by Let's Go Washington, the signature-gathering organization founded by Brian Heywood that has put several initiatives before Washington voters in recent years. Its official ballot title read: "AN ACT Relating to promoting energy choice by protecting access to gas for Washington homes and businesses." The summary voters actually saw was more specific: "This measure would repeal or prohibit certain laws and regulations that discourage natural gas use and/or promote electrification, and require certain utilities and local governments to provide natural gas to eligible customers."

In practice, according to the court's own description, I-2066 did four things. It required utilities, local governments, and the state Utilities and Transportation Commission to ensure continued natural gas access regardless of the availability of other energy sources, repealing sections of a 2024 law — the Washington Decarbonization Act for Large Combination Utilities — that would have mandated or incentivized electrification. It barred local governments and some utilities from taking any action that discourages or prohibits gas use. It changed statewide building and energy code goals, removing language directing new construction toward zero fossil-fuel greenhouse gas emissions by 2031. And it repealed a severability provision within the Decarbonization Act itself. Voters approved it 51.71% to 48.29% — roughly 1.94 million votes to 1.81 million — carrying 34 of the state's 39 counties.

Why the Court Struck It Down

The case reached the Supreme Court after King County Superior Court Judge Sandra Widlan ruled in March 2025 that I-2066 was unconstitutional on three separate grounds: that it covered more than one subject, that its title didn't disclose everything in it, and that it improperly amended existing law without restating it. The Supreme Court affirmed the ultimate outcome — the initiative is void — but on narrower grounds than the trial court used, addressing only the single-subject question and leaving the other two theories undecided.

Article II, section 19 of the Washington Constitution states that a bill "shall embrace one subject only, and that shall be expressed in the title." Writing for the majority, Chief Justice Debra Stephens found that I-2066 combined four subjects with "markedly distinct purposes and regulatory effects": protecting gas access, restricting local air-quality authority, changing building codes, and repealing the Decarbonization Act's severability clause. The court held these provisions lacked "horizontal rational unity" — a rational connection to each other, not merely to the initiative's general title — and that because they couldn't be severed from the rest of the measure without the court guessing at what voters would have wanted absent the flawed sections, the entire initiative had to fall together. Chief Justice Stephens was joined by Justices Whitener, González, Melody, and Montoya-Lewis, along with retired Justice Barbara Madsen, sitting by special assignment as a justice pro tempore.

What the Dissent Argued

The three dissenting justices — Justice Mungia, who wrote the dissent, joined by Justices Charles Johnson and Gordon McCloud — did not argue the whole initiative was constitutionally sound. Justice Mungia agreed that specific sections, dealing with silently amending existing law and repealing the Decarbonization Act's severability clause, were flawed. The disagreement was about the remedy. Rather than voiding the entire 21-page, 13-section measure, the dissent argued the flawed sections should have been severed and the remainder — which, in Mungia's words, "exclusively relates to protecting consumers' access to natural gas" — left standing, on the reasoning that "it can be reasonably believed that the voters would have passed the remaining sections" without the defective parts. The dissent closed: "I would uphold the remainder of I-2066 as constitutional. Accordingly, I dissent."

What This Means for Natural Gas in Washington, Right Now

The practical effect of this ruling is smaller than it might sound, for one specific reason: I-2066 never actually took effect. It passed in November 2024, was challenged in court almost immediately, and King County Superior Court voided it in March 2025 — about four months later — before any of its provisions went into force. It stayed blocked through the entire appeal. So the September 2026 ruling isn't reversing 18 months of a different natural-gas policy; it's the final confirmation of a legal status quo that has already been in place since spring 2025.

That status quo means the 2024 Washington Decarbonization Act for Large Combination Utilities remains fully in force — the law I-2066 was written to roll back. Utilities are still required to plan for and pursue cost-effective electrification of natural gas end-uses. Cities, counties, and air-quality regulators keep the authority I-2066 would have stripped to discourage or restrict gas hookups in new construction, which is the piece most directly relevant to local all-electric building codes. And the statewide building-code goal of zero fossil-fuel greenhouse gas emissions by 2031 stays on the books; I-2066 would have deleted that language, but the deletion never took effect. None of this reaches existing gas customers directly — nothing here disconnects anyone's current gas service or appliances. It governs utility infrastructure planning and new construction going forward, not what's already installed in an existing home or business.

Reaction broke along predictable lines. Greg Lane, executive vice president of the Building Industry Association of Washington, called the ruling "a direct rejection of the clearly expressed will of Washington voters." Let's Go Washington responded on social media in similarly combative terms. Neither organization has announced a redrafted, narrower version of I-2066 built to survive the single-subject problem — Let's Go Washington's three initiatives already on this November's ballot concern school athletics eligibility, parental rights in schools, and a state wealth tax, none of them natural gas. As of this writing, there's no sequel initiative in motion.

What's Actually on the Ballot This November

Five of the Washington Supreme Court's nine seats are up for election on November 3, 2026 — an unusually high number driven by a wave of retirements and appointments. Of the six justices in the majority on this ruling, two are seeking reelection this cycle: Chief Justice Stephens, who wrote the opinion, is running for Position 7 against three challengers; Justice Melody, who joined it, is running to retain Position 1, a seat she was appointed to after Justice Mary Yu's retirement, against one challenger. A third majority justice, Montoya-Lewis, holds a seat that is on this year's ballot but chose not to seek reelection herself, leaving two other candidates to compete for the open position. The remaining majority justices, González and Whitener, are not up this cycle at all, and Madsen — who sat on this case only as a retired justice by special assignment — has already left the court and isn't a candidate for anything.

Of the three dissenting justices, one, Charles Johnson, is leaving the court this year regardless of how he ruled, having reached the state's mandatory judicial retirement age of 75; his seat is also on the ballot, contested by two other candidates. Justices Mungia and Gordon McCloud are not up for election this cycle.

Where I Could Be Wrong

• This describes what the court held, not whether it held correctly. Article II, section 19's single-subject test is genuinely fact-specific and contested — Justice Mungia's dissent is a substantive legal argument, not a fringe one, and reasonable readings of "rational unity" between a measure's provisions can differ. I'm reporting the majority's reasoning and the dissent's, not adjudicating between them.
• The connection between this ruling and November's ballot is exactly what's described above, and no more. Two of the six majority justices are seeking reelection; a third's seat is open because she chose not to run, for reasons I found no evidence tie to this specific case. Any characterization — from any side — implying a broader "the justices who did this will answer to you" than that specific breakdown is overstating what's actually on the ballot.
• Washington's judicial elections are formally nonpartisan, and justices are not supposed to campaign on how they would rule in future cases. Whether invoking one ruling to mobilize voters for or against a candidate is an ordinary part of how that system functions in practice, or something closer to what the nonpartisan design is meant to avoid, is a real question this entry doesn't attempt to settle.
• I read the court's opinion directly — the majority's reasoning, the background section, and the dissent's closing pages — rather than relying solely on news summaries, but a 59-page opinion carries more than four sections of a blog entry can hold. The full reasoning on severability and the "horizontal and vertical rational unity" framework the majority adopted is worth reading in the original for anyone forming a view on whether the ruling was correct.

Sources

1. Washington Supreme Court. Climate Solutions, et al. v. State of Washington, et al., No. 104240-0, filed September 17, 2026. courts.wa.gov
2. Washington State Standard. WA high court tosses natural gas measure approved by voters. September 17, 2026. washingtonstatestandard.com
3. Washington State Standard. Judge overturns Washington natural gas measure approved by voters. March 21, 2025 (the King County Superior Court ruling that first blocked I-2066 from taking effect). washingtonstatestandard.com
4. KIRO 7 News. WA Supreme Court strikes down voter-approved natural gas initiative, drawing sharp reactions. September 17, 2026 (Building Industry Association and Let's Go Washington reaction). kiro7.com
5. Ballotpedia. Washington 2026 ballot measures. ballotpedia.org
6. Washington Secretary of State. November 5, 2024 General Election Results — Initiative Measure No. 2066, county breakdown. results.vote.wa.gov
7. Ballotpedia. Washington Initiative 2066, Natural Gas Policies Measure (2024). ballotpedia.org
8. KNKX Public Radio. Natural gas initiative won at the ballot box, but opponents plan to keep fighting it in court. November 14, 2024. knkx.org
9. Ballotpedia. Washington Supreme Court elections, 2026. ballotpedia.org
10. Wikipedia. 2026 Washington Supreme Court election. en.wikipedia.org
11. The Spokesman-Review. Debra L. Stephens, a candidate for Supreme Court Position 7, State of Washington in the 2026 Washington Primary Election, Aug. 4. spokesman.com