As usual, SCOTUSblog has an excellent recap of the Comstock opinions written by Stanford Law Student Eric Hansford. From the post:
The respondents in this case are federal prisoners who were about to be released when the government instituted civil commitment proceedings against them under Section 4248. When the respondents challenged (among other things) the constitutionality of the government’s actions, the district court held (again, among other things) that the statute exceeded Congress’s powers under Article I of the Constitution, and the Fourth Circuit affirmed on this ground.
The Supreme Court granted certiorari, and yesterday it reversed. In the majority’s view, “five considerations, taken together,” compel the conclusion that Article I’s Necessary and Proper Clause grants Congress authority sufficient to enact Section 4248.
Justice Alito also concurred in the judgment. In his view, there is a “substantial link” between Section 4248 and Congress’s enumerated powers, thereby rendering the statute a necessary and proper means of implementing federal criminal law statutes authorized by Congress’s other enumerated powers.