As to constitutional rights, there is diversity now of course … some states clearly have broader rights (pick your poison — obscenity, gun rights, criminal justice, etc.) pursuant to their state constitutions. The Federal Consitution sets a baseline.

Really it boils down to balancing. The ruling can’t be too narrow — the SC sets forth rules to apply in future cases, they accept cases in part because they aren’t TOO narrow. It is not a trial court that deals with sui generis facts. At least, often not.

Also, more unanimity is good .. up to a point … at least when that alternative is not only a 6-3 ruling, but many an unanimous one, but with various rationales. The worst, of course, might be religion cases with 4-2-3 sort breakdowns. But, handing down a bunch of extra-narrow 4A cases etc. can have diminishing returns too.

These new Constitutional prohibitions that are being found after hundreds of years in hiding do little to give the state courts any sense that the supremes actually have any coherent sense of what the Constitution says.

shouldn’t the constitution have a single meaning for all Americans? Should a person with an IQ of 63 (and of course the requisite adaptive skill deficits) receive constitutional protection from death sentences in Missouri but not Florida?

Or reframed in the opposite direction: absent an actual Constitutional prohibition, shouldn’t the community in Missouri be as much able to decide on appropriate punishments for heinous crimes as the community in Florida?