Antonin Scalia may be the Supreme Court justice whom progressives most love to hate. Daily Kos blogger Sylvia Moore says he is "clearly an authoritarian." A California Lawyer reader complains online that Scalia "actively promotes an authoritarian agenda in which the rights of the individual have little meaning." Even legal writer Joan Biskupic, in her relatively respectful and sympathetic biography of Scalia, refers to his "authoritarian bent" and "authoritarian instinct."

The latest refutation of this caricature is Maryland v. King, a decision issued Monday in which the Supreme Court upheld DNA testing of arrestees. Scalia's dissent illustrates how his respect for the Constitution leads him to side with the individual against the government—something that happens more often than you would expect based on his reputation.

The case involved Alonzo King, a Maryland man who was arrested in 2009 for threatening a group of people with a shotgun. As required by the Maryland DNA Collection Act, police swabbed his cheek for skin cells. Testing of the DNA on the swab linked King to a 2003 rape for which he was later convicted.

The majority opinion (which was joined by Stephen Breyer, usually identified as a member of the Court's "liberal wing") concedes that the forcible collection of a DNA sample from inside King's mouth constituted a search under the Fourth Amendment. But the majority says that search, although warrantless and not based on any expectation that it would discover evidence of the crime with which King had been charged, was "reasonable" because it was aimed at "identifying" him.

Scalia blows that rationale to smithereens in a scathing dissent joined by the Court's three most left-leaning members. "The Court's assertion that DNA is being taken, not to solve crimes, but to identify those in the State's custody, taxes the credulity of the credulous," he writes. "These DNA searches have nothing to do with identification."

The police already knew who King was, and the DNA test, the results of which were not available until four months after his arrest, did not confirm his identity. Rather, the test implicated him in another crime.

"If the Court's identification theory is not wrong," Scalia writes, "there is no such thing as error." And since "the Fourth Amendment forbids searching a person for evidence of a crime when there is no basis for believing the person is guilty of the crime or is in possession of incrimi­nating evidence," he concludes, Maryland's law is unconstitutional.

On other occasions Scalia has joined the majority in whittling away at the guarantee against unreasonable searches and seizures, especially in the name of the war on drugs. But he also has written majority opinions rejecting infrared surveillance of homes, GPS tracking of cars, and dog sniffs at doorsteps without probable cause.

Sentencing is another area where Scalia has shown concern for the rights of criminal defendants. He and Thomas led the charge against mandatory federal sentencing guidelines, insisting that the Sixth Amendment right to trial by jury means judges may not determine facts that automatically trigger harsher punishment.

In Hamdi v. Rumsfeld, the 2004 case involving an American citizen detained in the United States as an "enemy combatant," Scalia took the most radical position against the Bush administration, saying the government had to try Hamdi in civilian court or let him go. That is hardly the position of an authoritarian.

Scalia likewise has shown a decidedly non-authoritarian respect for freedom of speech in cases dealing with advertising, online indecency, flag burning, dog fight films, violent video games, and criticism of politicians. I would also count in his favor (although many progressives would not) his defense of the right to arms and his opposition to the abuse of eminent domain.

Scalia's record of resisting government encroachment on individual freedom is by no means perfect. But on the whole he is more liberal than some of his purportedly liberal colleagues.