"In 1972, the Supreme Court ruled that the Sixth Amendment guarantees a right to a unanimous jury – but that defendants in state trials do not have such a right."

"[Monday], by a vote of 6-3, the justices reversed course, holding that the Sixth Amendment establishes a right to a unanimous jury that applies in both federal and state courts. The ruling is significant not only for the inmates who were convicted by nonunanimous juries in Louisiana and Oregon, but also for the extent to which the justices were deeply splintered as they debated whether and when to overturn longstanding precedent.... Justice Neil Gorsuch wrote for the majority, in an opinion that was joined in full by Justices Ruth Bader Ginsburg and Stephen Breyer and in part by Justices Sonia Sotomayor and Brett Kavanaugh....  Kavanaugh filed a concurring opinion that focused on his views on the application of stare decisis to this case.... [The question is whether the precedent is] 'not just wrong, but grievously or egregiously wrong'... whether the prior precedent has 'caused significant jurisprudential or real-world consequences'... [and] whether people have relied on the earlier decision... Justice Clarence Thomas... wrote separately to argue that this right applies to the states through the 14th Amendment’s privileges or immunities clause, rather than the due process clause. Alito’s dissent [premised on stare decisis] was joined by Chief Justice John Roberts and (for the most part) Justice Elena Kagan...."

Writes Amy Howe at SCOTUSblog.

You might enjoy the NYT "Daily" podcast with Adam Liptak discussing the decision. He thinks that Justice Kagan joined the dissent because she cares about preserving other precedent, specifically the abortion-rights cases.

I was glad to see that 1972 case (Apodaca) overruled. It was always a stumbling block when trying to teach this area of constitutional law (the "incorporation" doctrine). I always tried to convey an understanding that the cases and doctrine — right or wrong — make sense. Whether you yourself would have decided the case the same way, you need to work to see how it made sense to the judges who decided it. All the effort I put into trying to understand Apodaca so I could express the sense of it coherently to students! If only I could have seen into the future and been able to say: Don't worry about Apodaca — it will be overruled in 2020.

Here's the full text of the new case, Ramos v. Louisiana. From the Gorsuch opinion:

Why do Louisiana and Oregon allow nonunanimous convictions? Though it’s hard to say why these laws persist, their origins are clear. Louisiana first endorsed nonunanimous verdicts for serious crimes at a constitutional convention in 1898. According to one committee chairman, the avowed purpose of that convention was to “establish the supremacy of the white race,” and the resulting document included many of the trappings of the Jim Crow era: a poll tax, a combined literacy and property ownership test, and a grandfather clause that in practice exempted white residents from the most onerous of these requirements....

Adopted in the 1930s, Oregon’s rule permitting nonunanimous verdicts can be similarly traced to the rise of the Ku Klux Klan and efforts to dilute “the influence of racial, ethnic, and religious minorities on Oregon juries.”... [B]oth Louisiana and Oregon have frankly acknowledged that race was a motivating factor....

The Sixth Amendment promises that “[i]n all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial, by an impartial jury of the State and district wherein the crime shall have been committed, which district shall have been previously ascertained by law.”...

Still, the promise of a jury trial surely meant something— otherwise, there would have been no reason to write it down.... Imagine a constitution that allowed a “jury trial” to mean nothing but a single person rubberstamping convictions without hearing any evidence.... The text and structure of the Constitution clearly suggest that the term “trial by an impartial jury” carried with it some meaning about the content and requirements of a jury trial.

One of these requirements was unanimity. Wherever we might look to determine what the term “trial by an impartial jury trial” meant at the time of the Sixth Amendment’s adoption—whether it’s the common law, state practices in the founding era, or opinions and treatises written soon afterward—the answer is unmistakable. A jury must reach a unanimous verdict in order to convict.

The requirement of juror unanimity emerged in 14th-century England and was soon accepted as a vital right protected by the common law. As Blackstone explained, no person could be found guilty of a serious crime unless “the truth of every accusation . . . should . . . be confirmed by the unanimous suffrage of twelve of his equals and neighbors, indifferently chosen, and superior to all suspicion.”A “ ‘verdict, taken from eleven, was no verdict’ ” at all.

This same rule applied in the young American States. Six State Constitutions explicitly required unanimity. Another four preserved the right to a jury trial in more general terms But the variations did not matter much; consistent with the common law, state courts appeared to regard unanimity as an essential feature of the jury trial.

It was against this backdrop that James Madison drafted and the States ratified the Sixth Amendment in 1791. By that time, unanimous verdicts had been required for about 400 years. If the term “trial by an impartial jury” carried any meaning at all, it surely included a requirement as long and widely accepted as unanimity....

Nor is this a case where the original public meaning was lost to time and only recently recovered....

There can be no question either that the Sixth Amendment’s unanimity requirement applies to state and federal criminal trials equally. This Court has long explained that the Sixth Amendment right to a jury trial is “fundamental to the American scheme of justice” and incorporated against the States under the Fourteenth Amendment. This Court has long explained, too, that incorporated provisions of the Bill of Rights bear the same content when asserted against States as they do when asserted against the federal government.So if the Sixth Amendment’s right to a jury trial requires a unanimous verdict to support a conviction in federal court, it requires no less in state court....