In Django Unchained, Quentin Tarantino's bloody new spaghetti western set in the pre-Civil War American South, Samuel L. Jackson portrays the despicable character of Stephen, the head house slave at a hellish Mississippi plantation. Without giving too much of the story away, suffice it to say Stephen emerges as one of the main enemies our hero Django, in a great performance by Jamie Foxx, must defeat while attempting to liberate his wife from bondage.

Reviewing the film for the Boston Globe, liberal critic Wesley Morris struggles to convey the villainy of Stephen's character, turning to a present-day comparison for help. "The movie is too modern for what Jackson is doing to be limited to 1858," Morris writes. "He's conjuring the house Negro, yes, but playing him as though he were Clarence Thomas… [a man who] some black people find embarrassing."

I realize that liberals like Morris have been saying all sorts of stupid things about Clarence Thomas for many years now—including the demonstrably false notion that Thomas is some sort of puppet of Justice Antonin Scalia (The New York Times once described Scalia as Thomas' "apparent mentor") when in fact Thomas is the one who has had an influence on Scalia's legal approach—but the cheapshot comparison here with Django's slave power system is particularly contemptible.

Morris may be too uninformed to know it, but the fact is no Supreme Court justice since Thurgood Marshall has written more frequently or powerfully about American racism than Thomas.

Consider his role in the 2003 case Virginia v. Black, which centered on a state law criminalizing the act of cross-burning when done "with the intent of intimidating any person or group of persons." While most of his colleagues seemed content during oral argument to view the case solely through the lens of First Amendment law, Thomas took a different view. The 1952 cross-burning act was intended to counteract "almost 100 years of lynching and activity in the South" by the Ku Klux Klan and other groups, he reminded the courtroom. "This was a reign of terror and the cross was a symbol of that reign of terror."

Several months later, in a lone dissent, Thomas went further, arguing that cross-burning was part and parcel of racist terrorism and therefore deserved no protection under the First Amendment. "Those who hate cannot terrorize and intimidate to make their point," he wrote.

It was not an opinion designed to warm the hearts of free speech absolutists, to be sure. But that doesn't disqualify it from the civil rights tradition. Nor would it be the last time Thomas offered a history lesson about race in America.

In 2010, for example, after the Supreme Court struck down certain campaign finance restrictions in Citizens United v. F.E.C., the majority in that case came under intense criticism from various liberal groups for harboring an alleged pro-corporate bias. In response, Thomas reminded champions of campaign finance regulation that their cause was not exactly squeaky clean.

"Go back and read why Tillman introduced that legislation," Thomas told an audience at Stetson University College of Law, referring to the Tillman Act of 1907, one of the earliest federal campaign finance regulations, sponsored by Sen. Benjamin Tillman, a leading Southern progressive and notorious white supremacist. "Tillman was from South Carolina," Thomas continued, "and as I hear the story he was concerned that the corporations, Republican corporations, were favorable toward blacks and he felt that there was a need to regulate them."

But that verbal jab is nothing compared to Thomas' contribution to the 2010 case of McDonald v. Chicago, where the Supreme Court ruled that the Second Amendment right to keep and bear arms applies against state and local governments via the 14th Amendment.

In his concurring opinion in that case, Thomas once again reached for the history books, this time tracing the 14th Amendment's origins to the antislavery movement and to the efforts of the Radical Republicans of the 39th Congress, who sought to force the former Confederate states to respect fundamental rights after the Civil War—including the right to keep and bear arms, a provision of particular importance to the recently freed slaves, who were now facing the South's incipient Jim Crow regime.

That focus on black history even earned Thomas a rare compliment from liberal Washington Post columnist Courtland Milloy, who marveled, "His advocacy for black self-defense is straight from the heart of Malcolm X," while likening the opinion to "a mix of black history lesson and Black Panther Party manifesto." Milloy's sentiment was accurate, though he should have reached further back for the comparison. Thomas' advocacy for black self-defense came straight from the heart of Frederick Douglass, whose writings Thomas repeatedly cited in the McDonald opinion. "The liberties of the American people were dependent upon the ballot-box, the jury-box, and the cartridge-box," Douglass once wrote. "Without these no class of people could live and flourish in this country."

Which brings us back to Wesley Morris' Django review. Had Morris bothered to glance at Thomas' jurisprudence, rather than opting for a lazy and ignorant smear, he would have discovered a writer whose work is steeped in African American history, and who grapples repeatedly with the long shadows cast by slavery and Jim Crow. Clarence Thomas may not qualify as a modern liberal, but there is no question he remains part of a civil rights tradition that started with Frederick Douglass.