Kavanaugh and Barrett side with liberal justices in 5–4 death penalty ruling, drawing sharp conservative dissent

The Supreme Court dismissed an Alabama death penalty case in a 5, 4 vote after Justices Brett Kavanaugh and Amy Coney Barrett broke from their conservative colleagues and joined the Court's three liberal members. The decision in Hamm v. Smith spares the life of defendant Joseph Smith and leaves intact a lower court finding that Smith is intellectually disabled, and therefore constitutionally shielded from execution.

The ruling landed with an unusual alignment. Four conservative justices dissented, with Justice Samuel Alito authoring the primary dissent and Justice Clarence Thomas filing a separate one that went further than any of his colleagues were willing to go. The majority issued no sweeping opinion. It simply dismissed the case as improvidently granted, legal shorthand for "we shouldn't have taken this up."

That procedural move denied Alabama the broader rule it sought and left the constitutional landscape around executing intellectually disabled defendants exactly where it was. For supporters of capital punishment and state sovereignty, the outcome is a missed opportunity. For the Court's liberal wing, it is a narrow but real win delivered by two Trump-appointed justices.

What Alabama asked for, and why it didn't get it

Twenty-five years ago, the Supreme Court held that executing intellectually disabled people constitutes cruel and unusual punishment under the Eighth Amendment. That precedent left states some room to define intellectual disability on their own terms but established a general threshold: an IQ below 70 typically qualifies.

Joseph Smith's case tested the edges of that line. Smith had multiple IQ scores ranging from 72 to 78, with a margin of error that dipped as low as 69. A lower court combined that lowest score with a broader review of Smith's condition and concluded he met the standard for intellectual disability.

Alabama wanted the Supreme Court to overturn that conclusion. The state pushed a theory that would let states weigh multiple IQ scores however they saw fit to land above 70. Slate's legal commentators reported that Alabama went so far as to argue states should be permitted to count only the highest score and discard the lowest, a method that would have effectively let the state engineer its way past the constitutional bar.

That argument appears to have backfired. Kavanaugh and Barrett both seemed frustrated with Alabama's approach during oral arguments, according to Slate legal writer Mark Joseph Stern. Rather than craft a new constitutional rule from what Stern called a legal "mess," the two justices opted to dismiss the case entirely.

The dissents: Alito pushes back, Thomas goes further

Justice Alito's dissent, joined by Chief Justice John Roberts, Thomas, and Justice Neil Gorsuch, made clear that four members of the Court were prepared to rule in Alabama's favor. Slate's Dahlia Lithwick noted the margin on the podcast Amicus:

"We have this dissent by Justice Samuel Alito, joined by Chief Justice John Roberts, Justice Clarence Thomas, and Justice Neil Gorsuch. They were happy to take this mess and use it to make strong arguments against the Eighth Amendment. This was pretty close to going 5, 4 the other way."

That four justices were ready to move the law in Alabama's direction underscores how close the case came to a very different result.

Thomas, however, filed a separate dissent that none of his fellow dissenters joined. In it, he argued that the Eighth Amendment poses no barrier whatsoever to executing intellectually disabled people and that the Court should overrule its own 25-year-old precedent. Roberts, Alito, and Gorsuch declined to sign onto that position, a notable signal about where even the Court's right flank draws its lines.

The split within the conservative bloc is worth watching. Kavanaugh and Barrett refused to reward what they apparently viewed as a poorly constructed legal argument from Alabama. The four dissenters, meanwhile, split between Alito's more measured objection and Thomas's call to tear down the precedent entirely. It is not a picture of a unified conservative majority on capital punishment.

Alabama's lawyering problem

Stern's assessment was blunt. He said the outcome may represent "yet another case that crashed into the shoals of Alabama's terrible lawyering." The state's position, that it should be free to cherry-pick the highest IQ score and ignore the rest, apparently struck even sympathetic justices as overreach.

Conservative jurists who support the death penalty and believe states deserve broad latitude in criminal justice still expect states to present workable legal theories. Alabama's argument amounted to asking the Court to let it define intellectual disability in whatever way produced the result it wanted. That kind of request makes it harder, not easier, for the Court to write durable law, and Kavanaugh and Barrett evidently declined to try.

The frustration is understandable from a conservative standpoint. When a state brings a weak case to the highest court in the land, it doesn't just lose that case. It forecloses the possibility of a well-reasoned ruling that might have advanced legitimate state interests. Alabama had a chance to push for clearer standards on IQ testing and intellectual disability determinations. Instead, it asked for a blank check.

The pattern is not unique to death penalty law. Across the political spectrum, Republican defections on policy questions often trace back not to ideological betrayal but to the specific vehicle chosen to carry the fight. Bad strategy produces bad outcomes regardless of which side brings it.

What the ruling does, and doesn't, settle

The practical result is narrow. Joseph Smith will not be executed. The lower court's finding that he is intellectually disabled stands. But the Supreme Court created no new rule, set no new standard, and offered no guidance to other states wrestling with similar cases.

Stern called the outcome "a reprieve" and credited Kavanaugh and Barrett with "a good sense" for refusing to build a constitutional rule out of a flawed case. That is one way to read it. Another is that the Court punted, and that the underlying question about how states should handle borderline IQ scores in death penalty cases remains wide open.

The 25-year-old precedent barring execution of intellectually disabled defendants survives intact. Thomas's separate dissent signals that at least one justice would like to revisit it entirely. But with Kavanaugh and Barrett unwilling to move in that direction on this record, the precedent appears safe for now.

A 5, 4 court, not a 6, 3 court

The decision reinforces a reality that has been emerging across several terms: the conservative supermajority is not a monolith. Kavanaugh and Barrett have shown a willingness to break from the right-most members of the Court when they believe the facts or the legal arguments don't support a sweeping ruling. That independence frustrates some conservatives. It also reflects a judicial temperament that values institutional credibility over ideological lockstep.

Lithwick described the current bench as "a 3, 3, 3 court", three liberals, three hard-right conservatives, and three justices (presumably Kavanaugh, Barrett, and Roberts) who move between the blocs depending on the case. Whether that framing holds up across future terms remains to be seen, but Hamm v. Smith fits the pattern.

For conservatives who want the Court to move decisively on capital punishment, the message is clear: bring better cases. The votes may be there for a well-argued challenge to how states assess intellectual disability. They were not there for Alabama's approach of asking the Court to let states ignore inconvenient test scores.

The death penalty is not going away because of this ruling. Neither is the constitutional protection for intellectually disabled defendants. What went away was Alabama's shot at rewriting the rules, and the state has mostly itself to blame for that.