The Supreme Court has decided an important case about the meaning of constitutional rights and federalism.

Danforth v. Minnesota is about whether state courts, when they apply "new" rules of federal constitutional law, must also follow the federal law about the retroactive effect of those rights. This is an application of the Teague doctrine: When a state court conviction has become final, federal courts may review it in a habeas case, but for the most part, it will suffice if the state court applied the federal constitutional law that the U.S. Supreme Court had articulated at the time. That means that if there are Supreme Court cases that came out after the conviction became final, unless an exception applies, there will be no habeas relief in federal court. But what if the post-conviction litigation takes place in state court? Why can't the state follow its own law about whether there should be a new trial that meets the standards set in the new Supreme Court case?

In my old posts — here and here — I said I thought that originalism and federalism justified allowing the state court to function independently.

In today's opinion the majority recognizes the state courts' power to use state law to give more retroactive effect to federal constitutional rights. Justice Stevens writes the opinion:

It is... abundantly clear that the Teague rule of nonretroactivity was fashioned to achieve the goals of federal habeas while minimizing federal intrusion into state criminal proceedings. It was intended to limit the authority of federal courts to overturn state convictions—not to limit a state court’s authority to grant relief for violations of new rules of constitutional law when reviewing its own State’s convictions....

[T]he States that give broader retroactive effect to this Court’s new rules of criminal procedure do not do so by misconstruing the federal Teague standard. Rather, they have developed state law to govern retroactivity in state postconviction proceedings....

A decision by this Court that a new rule does not apply retroactively under Teague does not imply that there was no right and thus no violation of that right at the time of trial—only that no remedy will be provided in federal habeas courts. It is fully consistent with a government of laws to recognize that the finality of a judgment may bar relief. It would be quite wrong to assume, however, that the question whether constitutional violations occurred in trials conducted before a certain date depends on how much time was required to complete the appellate process.

This all seems so crashingly correct to me — and let me say that I've been teaching Federal Courts for more than 20 years — that I'm puzzled to see that Chief Justice Roberts has dissented. But I can't write more about this now. I will have to update this a little later.