I'll have more to write about the ruling soon, but the central question of the ruling, for me, is the same as the central question of last year's ruling in Gonzales v. Carhart: When the Supreme Court is interpreting scientific data, on which side should it err?
In Gonzales, the question was whether live intact D&X ("partial-birth abortion") is sometimes medically safer for women undergoing a second-trimester abortion or an emergency third-trimester abortion. If it were medically safer than other forms of D&X, then a restriction on the procedure would pose an undue burden on a woman's right to choose, violating Roe v. Wade and subsequent precedents. If it were not medically safer than other forms of D&X, then banning the procedure would have no impact on a woman's right to choose. The Supreme Court held that unless it can be demonstrated that live intact D&X is necessary, then the undue burden standard is not violated. This is why the federal ban on so-called partial birth abortions was upheld.
The Court's ruling this week in Baze v. Rees adopts a similar standard. Because it cannot be shown that another form of lethal injection poses a substantially lesser risk of inflicting unnecessary pain on a prisoner, the Court is predisposed to favor the current method. As Chief Justice John Roberts wrote, his opinion is that overturning the three-drug cocktail method...
...would threaten to transform courts into boards of inquiry charged with determining "best practices" for executions, with each ruling supplanted by another round of litigation touting a new and improved methodology. Such an approach finds no support in our cases, would embroil the courts in ongoing scientific controversies beyond their expertise, and would substantially intrude on the role of state legislatures in implementing their execution procedures—a role that by all accounts the States have fulfilled with an earnest desire to provide for a progressively more humane manner of death.It is worth noting that the chief justice is writing only for himself, Justice Anthony Kennedy (who wrote the Gonzales majority ruling), and Justice Samuel Alito, and not for all seven justices who upheld the three-drug standard. The ruling produced seven different opinions, and left substantial room for further discussion. More on that later.
For now it is sufficient to say that Chief Justice Roberts, Justice Alito, and Justice Kennedy hold the position that where scientific evidence on a given issue is disputed, the Court must err on the side of judicial restraint--or, to put it another way, on the side of a narrower interpretation of the Bill of Rights. This issue is not likely to come up often, but the role of science, and how the Supreme Court addresses (or refuses to address) scientific controversies, is already becoming central to the Roberts Court.