But it was in a third case, Walker v. Texas Division, Sons of Confederate Veterans, Inc., that Thomas made his voice heard most clearly—by his silence. In Walker, Thomas defected from the very First Amendment orthodoxy he defended in Reed. Remarkably enough, he joined the Court’s four moderate-liberals—Justices Ruth Bader Ginsburg, Stephen Breyer, Sonia Sotomayor, and Elena Kagan—to provide a decisive vote to allow the state of Texas to refuse to print a specialty license plate bearing the much-loved and hated Confederate battle flag. In an opinion by Breyer, the 5-4 majority held that a government can, with few limits, decide to convey any license-plate message it wants, and bar any that it disapproves. This isn’t “content-based” regulation of speech; the plate is speech by the government itself, and the First Amendment does not apply.

In Walker, Justice Samuel Alito wrote a dissent that could have come from Thomas’s pen. Alito argued that Texas’s rejection of the battle flag was “blatant viewpoint discrimination”—which is, in First Amendment doctrine, worse than the Sign Code in Gilbert.

Thomas goes his own way in most areas of the law he cares about—particularly in constitutional issues. He does not mind bucking even his closest allies—witness the sedate but impassioned brawl between Thomas and Justice Antonin Scalia found in their dueling opinions in Zivotofsky v. Kerry, the Jerusalem-passport case decided last week. Scalia, in dissent, thought it plain that Congress could require the president to stamp “Israel” on passports as the birthplace of American citizens born in Jerusalem; Thomas, concurring with the majority but writing only for himself, argued that the statute violated the president’s “residual foreign affairs powers” (whatever they are) but that Congress could require the president to stamp Jerusalem on the same person’s “Consular Record of Birth Abroad.” It was an opinion that pleased neither side entirely, and puzzled many quite a bit.

Why would Thomas cross over in the Sons of Confederate Veterans case? To state the obvious, Thomas is the Court’s only African American. Much has been made of his rejection of contemporary civil-rights orthodoxy. But it is equally clear that Thomas retains vivid and bitter memories of his poverty-stricken childhood in the Jim Crow South—and that he retains a particular hatred for the symbols of Southern white supremacy.

Thomas’s most powerful moment on the bench occurred in a case concerning a similar symbol—the burning cross. The year was 2002; Virginia v. Black was a challenge to a Virginia criminal statute that forbade burning a cross with the intent to intimidate another person. A decade before, the Court had struck down a local ordinance in St. Paul, Minnesota, that made it a crime to use symbols to arouse “anger, alarm or resentment in others on the basis of race, color, creed, religion or gender.” Scalia’s angry majority opinion broadly rejected “hate speech” regulation as “viewpoint based,” arguing that, “St. Paul has no such authority to license one side of a debate to fight freestyle, while requiring the other to follow Marquis of Queensbury Rules.”