The Supreme Court has ruled that the Controlled Substances Act does not give the Attorney General the authority to pre-empt or override state laws permitting doctors to assist those who wish to use drugs to end their own lives. Chief Justice Roberts, Scalia, and Thomas dissent.

This is part and parcel of what Ernest Young called the Rehnquist Court's "Two Federalisms". The "conservative" wing of the court reins in federal lawmaking power (on rare occasion) in the name of federalism, finding judicially enforceable limits on the enumerated powers where others find none. Meanwhile, some of the more liberal justices, including Justice Kennedy, try to uphold federalism on a more case-by-case basis, perhaps in compensation for their somewhat broader view of federal power.

Now, whether it is better for judges to enforce federalism principles (if they should enforce them at all) through hard constitutional rule or soft interpretive nudge is an interesting question (or both), beyond the scope of this post. More as I read the opinion, although probably not until after I finish my last exam.