Supreme Court DUCKS Deadly IQ Ruling

Interior view of an empty courtroom with wooden benches and a judges bench

The most powerful court in America just tiptoed away from the hardest question in capital punishment: how “smart” do you have to be before the state can kill you.

Story Snapshot

The Supreme Court refused to settle what IQ range makes someone execution-eligible, despite years of precedent warning against rigid cutoffs.
Earlier rulings already said a hard IQ line, like Florida’s old “70 rule,” violates the Constitution because IQ scores are imprecise.
Medical experts insist real intellectual disability is about life skills and lifelong limitations, not just a test number.^[2]
The Court’s silence leaves death-row inmates at the mercy of which state they drew and which judge happens to read the science correctly.^[3]^[4]

The Question The Justices Know Is Deadly Simple And Politically Toxic

Every capital case with borderline intelligence pushes the same blunt question: does one number on an IQ report decide who lives and who dies. The Supreme Court already ruled in Hall v. Florida that a rigid cutoff of 70 is unconstitutional because IQ is an estimate, not a divine score carved in stone. The justices said states cannot treat a score as “final and conclusive” when the test’s margin of error means 71 could, in reality, be 66 or 76.

That should have settled it, but it did not. States adjusted their laws just enough to claim compliance while still clinging to bright lines whenever possible. Florida’s statute once blocked defendants from even presenting evidence of disability unless they first showed a score of 70 or below. Hall struck that down, yet prosecutors around the country still argue in court that multiple scores in the low 70s prove someone is “not that disabled,” and some judges agree.^[2]^[4]

Why Doctors Do Not Treat IQ Like A Gas Gauge

Psychologists and psychiatrists diagnose intellectual disability using three pillars: below-average intellectual functioning, deficits in adaptive behavior, and onset before age eighteen. That second pillar, adaptive behavior, covers everyday life: managing money, holding a simple job, understanding time, handling basic self-care. The American Psychological Association and American Psychiatric Association told the Court that a proper diagnosis requires a full clinical workup, not just an IQ printout.^[2]

Under modern diagnostic manuals, a score just above 70 does not end the conversation; it starts one.^[2] A person can test in the low 70s and still meet criteria if their adaptive functioning is severely limited and those problems showed up in childhood.^[2]^[3] Hall recognized this reality, requiring courts to consider adaptive deficits whenever scores fall in the 70–75 range because the test’s built‑in error makes neat lines dishonest. That is basic science; pretending otherwise is legal fiction.

How A Case About Multiple IQ Scores Cornered The Court

The recent fight the Court stepped away from grew out of that messy scientific truth. Defendants often have several IQ scores over time, sometimes ranging from the high 60s into the upper 70s.^[2]^[4] In Hamm v. Smith, the defendant’s scores reportedly ranged from 72 to 78, and a lower court treated those numbers as defeating his intellectual-disability claim. Civil-rights advocates argued judges must read those scores as a band, then look hard at real‑world functioning.^[3]^[4]

The United States, in a friend-of-the-court brief, defended states’ leeway to rely heavily on scores and to keep the burden on the prisoner to prove disability.^[4] That position leans into administrability: government lawyers prefer clear thresholds that close the door to endless litigation. But Hall already rejected using the lowest endpoint of the lowest score’s range as a magic key and demanded a holistic assessment instead.^[4] The conflict between convenience and constitutional caution could not be sharper.

Why The Court’s “Duck” Matters More Than A New Rule Would

By declining to issue a fresh, bright-line rule, the Supreme Court effectively told Americans: we said enough in Hall; the rest is up to the lower courts. That might sound cautious, but in capital cases, silence has consequences. When an inmate’s life hinges on how one judge feels about the difference between 71 and 69, the risk of error is not theoretical. Hall warned that rigid approaches create an “unacceptable risk” that the intellectually disabled will be executed, which the Eighth Amendment does not tolerate.

Breaking: The U.S. Supreme Court struck down a stay of execution for Texas death row inmate Edward Busby on Thursday, clearing the way for his execution tonight amid concerns of his ineligibility due to intellectual disability. https://t.co/tB6dqZrut3

— Texas Tribune (@TexasTribune) May 14, 2026

From a common-sense, conservative perspective, the federal government should not micromanage every clinical dispute, but it also should not hide behind neat numbers when a mistaken guess means an irreversible death. State sovereignty is important; so is human fallibility. A rule that pretends IQ tests are infallible tools invites exactly the kind of bureaucratic cruelty most Americans reject once they see the facts. The Constitution’s promise is not perfection, but it certainly is not blind arithmetic.