The Twenty-First Amendment is the one that repealed Prohibition. Section two of that amendment has language in it suggesting that states might have super duper rights to restrict alcohol within their borders, even to the degree that the regulation might otherwise interfere with rights protected by other parts of the Constitution, such as the First Amendment, the Fourteenth Amendment, and the Dormant Commerce Clause, which prohibits states from discriminating in favor of local economic interests.
In my book, I have a chapter on this really interesting amendment and the cases decided by the Supreme Court that have shifted positions over the years. The Court used to say that section two did give states special rights to regulate alcohol; in more recent years, the Court has cut back on that view. Most recently, in a case called Granholm v. Heald, the Court said that the Twenty First Amendment does not authorize states to prohibit out-of-state alcohol producers from selling directly to consumers while allowing in-state producers from doing so.
In early 2010, the Fifth Circuit Court of Appeals in Texas decided the case of Steen v. Wine Country Gift Baskets.com, where it held that under Granholm, it was not a violation of the Dormant Commerce Clause for Texas to prohibit out of state retailers (not producers like in Granholm) from shipping directly to Texas consumers while allowing Texas retailers to ship directly to Texas consumers. Producers and retailers, the court held, were differently situated for constitutional purposes.
Wine Country filed for certiorari in the Supreme Court. Lots of big time lawyers were involved. Probably the foremost scholar of the Twenty First Amendment submitted a brief saying the Fifth Circuit got it wrong. The Court apparently held onto the case for a good while, considering it at several different conferences, but ultimately, last Monday, it denied cert without comment.