Analysis: Idaho Supreme Court appears likely to uphold parental choice tax credit

The Idaho Supreme Court heard oral arguments today in the legal challenge to Idaho’s Parental Choice Tax Credit, and the clearest takeaway from the courtroom was this: the justices appeared deeply unconvinced by the sweeping constitutional theory advanced by the state teachers union and its allies.

VIDEO: Justices had a variety of questions, but centered arguments on standing a one letter in the state constitution

Mountain States Policy Center was in the courtroom as petitioners and the state made their case. While courts rarely tip their hand definitively during oral argument, the justices’ questioning often reveals what they are struggling with—and in this hearing, the struggle was plainly on the petitioners’ side of the ledger.

Over and over, justices pressed on two major problems: whether petitioners even have standing to bring the case at all, and whether Idaho’s Constitution truly can be read to prohibit the state from supporting an education policy outside the public school system.

Those two issues—standing and the Constitution’s scope—may ultimately decide the case.

Background

Petitioners didn’t file a normal lawsuit seeking a ruling after the program took effect. They asked the Idaho Supreme Court for a writ of prohibition designed to stop implementation before the Parental Choice Tax Credit can even begin.

In their filings, they repeatedly emphasized the urgency of the case and urged the Court to intervene before applications opened. The framing matters, because extraordinary relief requires extraordinary justification—and today the Court appeared skeptical that petitioners had met that burden.

The petitioners’ constitutional argument rests on a claim that Idaho’s Constitution permits only one education system: the public schools. In the petitioners’ telling, the Parental Choice Tax Credit is not merely bad policy, but constitutionally forbidden because it allegedly establishes a “separate system” outside the “general, uniform and thorough” system the Constitution requires.

But as the hearing unfolded, the justices raised foundational questions about whether that theory aligns with the text, structure, and history of Idaho’s Constitution—or whether it attempts to convert a constitutional duty into a constitutional prohibition.

The core argument against

Petitioners’ legal position is blunt: they argue the Idaho Constitution mandates a single education system and grants the Legislature “no authority” to fund any education program outside it.

They also argue the Parental Choice Tax Credit “essentially creates a system” of private schools and a parallel network of education providers.

The strategy is obvious. If petitioners can convince the Court the tax credit is actually the creation of a separate school system, it becomes easier for them to argue it violates Article IX.

But the justices spent much of the hearing poking holes in that characterization—challenging both the “separate system” label and the logic behind it.

One of the most important moments came when petitioners’ attorneys argued that the Constitution creates “one system.” Justice Zahn pushed back directly: “It says A system.” That small distinction is huge. The Constitution’s text does not say “one and only one system.” It says the Legislature must establish and maintain “a” system of public schools.

Zahn’s questioning moved beyond grammar. She pressed petitioners on constitutional history: if the framers meant to prohibit other education supports, why wouldn’t they have said so explicitly?

This line of questioning matters because petitioners are effectively asking the Court to read a prohibition into Article IX that simply isn’t written there.

"Walk and chew gum"

Another moment that will likely define coverage of today’s hearing came from Justice Mueller.

Mueller questioned whether petitioners’ theory really makes sense: can’t Idaho “walk and chew gum at the same time”—maintaining public schools while also supporting an ancillary education program?

That’s the heart of the case.

Petitioners want the Court to accept a false choice: either Idaho funds public schools or it supports parental choice—but it can’t do both.

But Idaho’s constitutional duty to maintain public schools does not naturally convert into a ban on additional education policies. And the justices seemed aware of what would happen if petitioners’ view were adopted: it would constitutionalize a monopoly and freeze education policy in place indefinitely, preventing the Legislature from trying anything outside the traditional system even if it still fully supports that system.

"The system" claim

To fit their constitutional theory, petitioners need the Parental Choice Tax Credit to look like a state-run education apparatus. But the law is a tax policy that does not regulate schools into existence.

Justice Meyer reportedly observed there is nothing in HB 93 that “sets up a system,” precisely because it does not regulate.

Justice Mueller agreed that calling it a “system” was an exaggeration.

This point matters because petitioners are building their entire case on the idea that the Legislature created a parallel school system. If the Court sees it as simply a tax credit that parents may use for certain educational expenses, the constitutional framing collapses.

And one of today’s most telling exchanges underscored how far petitioners were willing to take their argument: when a justice asked whether petitioners were also challenging the provisions that could help parents with tutoring and other educational needs, petitioners reportedly confirmed they wanted the entire bill struck.

That response will likely resonate outside the courtroom. It suggests the lawsuit is not narrowly tailored to resolve a specific constitutional issue—it is an all-or-nothing attempt to eliminate education choice entirely, even where it supports students in ways that don’t resemble private school tuition.

Standing

Perhaps the most ominous sign for petitioners was how often the justices returned to standing.

Standing is not a mere procedural hurdle. It is a core requirement of judicial legitimacy: courts decide concrete disputes where plaintiffs can show a particularized injury, not broad policy disputes where groups ask judges to substitute their preferences for lawmakers’ decisions.

And today, multiple justices appeared unconvinced petitioners had shown the kind of direct injury that justifies the extraordinary relief they’re requesting.

Justice Zahn repeatedly asked variations of the same question: “What’s the injury here?” She also questioned whether petitioners had standing at all. Petitioners reportedly asked the Court for “relaxed standing,” and even conceded that not all petitioners may have standing.

Justice Mueller put the problem in stark terms: when petitioners pointed to legislators who signed on, Mueller noted those legislators don’t have standing—and told petitioners, “it seems you’ve weakened your case.” The Court also pressed petitioners: who is your best petitioner? Petitioners stumbled, but then landed on the teachers union first—only to be asked why the school district itself wasn’t the better plaintiff.

The accumulation of those questions is hard to ignore. Courts don’t spend that much time probing standing unless they think it could decide the case.

The state's case

The state’s argument—as reflected in the thread and echoed in the themes raised by MSPC’s amicus brief—centered on a straightforward constitutional principle: Article IX imposes a duty to maintain public schools; it does not impose a prohibition on everything else.

The state argued the program advances education, and nothing in the Constitution prevents it. They urged the Court not to read Article IX as a limitation. They emphasized the Legislature’s plenary power to legislate and argued the founders did not create a constitutional regime where public schools are the “end all, be all.”

Those arguments are significant because they realign the debate around what courts normally do. Courts enforce constitutional limits when they exist. They do not invent limits to foreclose new policy experiments that lawmakers are otherwise empowered to pursue.

And in one of the clearest intersections between MSPC’s work and the hearing, the state cited MSPC polling on public support. That matters not because popularity decides constitutionality—but because petitioners have framed the credit as an illegitimate end-run around public education. The polling demonstrates the opposite: Idahoans broadly see parental choice support as a legitimate public purpose.

Even more importantly, the state repeated a phrase that has been central to MSPC’s argument from the beginning: Article IX is a floor, not a ceiling.

Our influence

MSPC’s influence in the hearing was visible in at least three ways.

First, the state referenced MSPC’s polling to establish that Idahoans perceive educational choice support as serving a public purpose—not undermining one.

Second, the Court’s questioning directly tracked the conceptual frame advanced in MSPC’s amicus brief: whether the public school clause is a baseline obligation or a strict limitation barring other education programs. The hearing made clear several justices are leaning toward the baseline view.

Third, the “collateral damage” argument was not hypothetical in today’s courtroom. Justices raised concerns that petitioners’ logic could endanger other state programs. A justice pointed out the potential impact on Idaho Launch, and Justice Zahn flagged other programs that could be implicated if petitioners’ theory becomes law.

That is one of the most important parts of the case: petitioners are not merely asking the Court to strike HB 93; they are asking the Court to adopt a constitutional interpretation that could ripple across tax policy, education policy, and the Legislature’s ability to experiment in the future.

The most likely outcome

Predicting a Supreme Court decision is always risky. Oral argument is not a vote count.

But the signals from today’s hearing point to two plausible paths.

The first is a decision that petitioners lack standing. The repeated standing questions—especially petitioners’ request for “relaxed standing” and the Court pressing for a “best petitioner”—suggest standing is a real vulnerability. If the Court resolves the case there, the program survives without the Court needing to reach the broader constitutional debate.

The second is a decision on the merits rejecting petitioners’ “one system” theory and affirming that Idaho may maintain public schools while also supporting ancillary educational opportunities. Justice Mueller’s “walk and chew gum” framing captures that conclusion neatly: the state’s duty to maintain public schools does not prevent it from doing other things that advance education.

Either way, petitioners seemed to face an uphill climb. They were not only defending a maximalist reading of Article IX; they were also asking for extraordinary relief on an accelerated timeline, with standing questions hanging over the entire case.

The Court’s skepticism today suggests it is not eager to become a policymaking institution—especially not one rewriting the Constitution to prohibit the Legislature from serving Idaho families in new ways.

And that, in the end, may be the most important lesson from today’s hearing: the Idaho Supreme Court looked less like a court ready to strike down the Parental Choice Tax Credit—and more like a court looking for a principled way to keep constitutional law from being used as a blunt instrument against lawful, popular, and parent-driven education reforms.