In his plurality opinion in yesterday's free-speech case, McCutcheon v. Federal Election Commission, Chief Justice John Roberts notes an anomaly in contemporary "liberal" First Amendment jurisprudence: "If the First Amendment protects flag burning, funeral protests, and Nazi parades--despite the profound offense such spectacles cause--it surely protects political campaign speech despite popular opposition."

We'd take the point a step further. The examples Roberts cites all involve fringe political expression. But the First Amendment also protects outré speech outside the political realm--most notably pornography, the subject of a great deal of Supreme Court jurisprudence over the past few decades, in which judicial liberals took the lead in expanding free-speech rights.

In recent years something of a consensus has emerged. When the court extended First Amendment protection to "depictions of animal cruelty" (U.S. v. Stevens, 2010) and violent video games (Brown v. Entertainment Merchants Association, 2011), the decisions were written by Roberts and Justice Antonin Scalia, respectively, for 8-1 and 7-2 majorities.

So why have the court's "liberals" adopted a hostile attitude toward political speech, which has long been understood as being at the core of First Amendment protection? In his McCutcheon dissent, Justice Stephen Breyer elaborates the theory behind this odd development.

We should note that Breyer has proved more willing than his liberal colleagues to uphold restrictions on nonpolitical speech. He was one of the two dissenters (with Justice Clarence Thomas) in Brown v. EMA, which involved a statute restricting sales of games to minors. He also dissented in U.S. v. Playboy Entertainment Group (2000), which invalidated limits on sexually explicit cable TV programming.