Mitchell v. Helms
In this opinion (unfortunately just a plurality), Justice Thomas holds that it does not violate the Establishment Clause for the federal government to run a program that lends educational materials to private schools, including religious schools. He makes the excellent point that "the religious nature of a recipient should not matter to the constitutional analysis, so long as the recipient adequately furthers the government's secular purpose. . . . If a program offers permissible aid to the religious (including the pervasively sectarian), the areligious, and the irreligious, it is a mystery which view of religion the government has established, and thus a mystery what the constitutional violation would be. The pervasively sectarian recipient has not received any special favor, and it is most bizarre that the Court would, as the dissent seemingly does, reserve special hostility for those who take their religion seriously, who think that their religion should affect the whole of their lives, or who make the mistake of being effective in transmitting their views to children."
In what I think is the best passage of the opinion, Justice Thomas traces the "pervasively sectarian" inquiry back to nativist anti-Catholicism of the 19th century. He concludes: "[N]othing in the Establishment Clause requires the exclusion of pervasively sectarian schools from otherwise permissible aid programs, and other doctrines of this Court bar it. This doctrine, born of bigotry, should be buried now."
Good News Club v. Milford Central School
Proving once again that it is the conservative wing of the Supreme Court that cares most about free speech, this opinion by Justice Thomas held that a public school violated the 1st Amendment when it banned a religious club from meeting on campus after school hours, even though other clubs were free to meet. Amazingly, the Second Circuit had held that the school COULD ban the club, even though the case was clearly controlled by Lamb's Chapel v. Moriches (another Supreme Court reversal of the Second Circuit). The school had argued, "Hey, we're only trying to avoid violating the Establishment Clause." Justice Thomas dismisses this rather silly argument by noting that there was no coercion involved, and that it would create a "heckler's veto" if the school worried too much about (mis)perceived endorsement of the club's message. Moreover, said the Court, "we cannot say the danger that children would misperceive the endorsement of religion is any greater than the danger that they would perceive a hostility toward the religious viewpoint if the Club were excluded from the public forum." Exactly.
City of Indianapolis v. Edmond
In this case, the Court (per Justice O'Connor) held that it violated the Fourth Amendment's ban on unreasonable searches and seizures for a state to set up a roadblock to search drivers for illegal drug use. The Court had to take care, however, to distinguish two cases that might have seemed on point -- Michigan Dept. of State Police v. Sitz (upholding roadblocks to search for drunk drivers) and United States v. Martinez-Fuerte (upholding roadblocks to search for illegal immigrants).
The really interesting opinion here is Justice Thomas's dissent, where he briefly makes two points: 1) This case was indeed controlled by Sitz and Martinez-Fuerte; and 2) Sitz and Martinez-Fuerte, however, should be overruled. "Indeed," says Thomas, "I rather doubt that the Framers of the Fourth Amendment would have considered "reasonable" a program of indiscriminate stops of individuals not suspected of wrongdoing."
As is becoming more common, Justice Thomas stakes out a position on a matter of criminal procedure that is both unique and more "liberal" than the rest of the Court. And he is led to a more "liberal" position because of his consistent commitment to originalism. Are the liberal opponents of originalism paying attention?
United States v. Hubbell
This case concerned whether the government could subpoena documents and use them to prosecute one of Clinton's jailbound cronies, Webster Hubbell. The constitutional amendment in question was the Fifth: no person shall be "compelled in any criminal case to be a witness against himself." The Court first noted that subpoenaing documents often doesn't violate this provision, because a) the production of documents is not "testimonial" in character, and b) the witness was not "compelled" to create the documents in the first instance. It then noted, however, that the so-called "act of production" doctrine can be used to exclude documents if the very act of production itself has a "compelled testimonial aspect."
The ultimate outcome of this particular case is not important. What is fascinating is that Justice Thomas (followed by Scalia) wrote a separate concurrence in which he argued that based on extensive analysis of originalist materials, the Fifth Amendment should protect against the production of ANY incriminating evidence, unlimited by the Court's "compelled testimonial aspect." He analyzes the word "witness" as used around the time of the Framing, concluding that it applies equally to documents.
Once again, Justice Thomas takes a position more "liberal" on criminal matters, due to his consistent originalism.
This list is obviously very incomplete; I'll add some more Thomas opinions as I have time.