The Institute for Justice won another case before the Supreme Court. This one dealt with interstate wine shipments and whether states could prohibit interstate wines shipments to their residents yet allow intrastate shipments by local wineries.
The Court split 5-4 on this: the majority (Kennedy [author of the Court's opinion], Scalia, Ginsburg, Souter and Breyer) held that "states do not have the authority to regulate liquor simply to protect their economic interests."
The minority (Thomas [author of the lone dissent], Rehnquist, O'Connor and Stevens) said the 21st Amendment gave states the authority to regulate alcoholic beverages as they see fit. This overstates the issue, to say the least. The state regulations at issue were not aimed at protecting minors or minimizing consumption; they were designed to protect in-state wineries from out-of-state competition. That's impermissible under the Commerce Clause.