What’s the standard of review for a federal habeas court considering whether a state court has properly found a constitutional error harmless? Well, actually, now a habeas petitioner must satisfy two different standards. He or she must show (1) that the state court unreasonably applied Chapman and (2) that the error was not harmless under the Brecht standard, a more prosecution-friendly test than Chapman‘s “beyond a reasonable doubt” harmlessness burden.
For more on the interplay of the two tests, see our prior post. The upshot of this decision is that a habeas court can’t grant relief where a state court has found a constitutional error harmless unless it holds two things. First, it must conclude that the state court’s finding that the error was harmless beyond a reasonable doubt is not just wrong, but unreasonable (that is, Chapman + AEDPA deference). It must also conclude on its own that it holds “grave doubt” about whether the error affected the outcome of the trial (the Brecht harmlessness test that applies in all habeas cases).
You may ask, “why does this matter?” You wouldn’t be alone in this; the dissent asserts that any case satisfying the Brecht standard will necessarily satisfy the Chapman + AEDPA test. And though the majority insists that it does matter, it cannot fabricate a convincing hypothetical to illustrate its point.
So yes, there’s a distinct angels-on-the-head-of-a-pin flavor to the substantive holding here. There are two aspects of the decision that may be more significant than the black-letter rule announced. One is the majority’s cavalier treatment of SCOTUS precedent. The opinion denies that it is contradicting the Court’s two prior (unanimous) proclamations on this point. This is a laughable claim. See Fry v. Pliler, 551 U.S. 112 (2007) (“it certainly makes no sense to require formal application of both tests (AEDPA/Chapman and Brecht) when the latter obviously subsumes the former); Davis v. Ayala, 135 S. Ct. 2187 (2015) (“a prisoner who seeks federal habeas corpus relief must satisfy Brecht, and if the state court adjudicated his claim on the merits, the Brecht test subsumes the limitations imposed by AEDPA“).
Also of note: this case is another example of the Court’s growing hostility to claims for postconviction relief. It hasn’t been a good term for habeas, and the dissent hints that this may only be the beginning, warning that the majority’s analysis here may not be aimed so much as the question before it, but at generating “more succulent fruit in cases to come.”