I write separately to offer an originalist de- fense of the colorblind Constitution; to explain further the flaws of the Court’s Grutter jurisprudence; to clarify that all forms of discrimination based on race—including so-called affirmative action—are prohibited under the Constitution; and to emphasize the pernicious effects of all such discrimination.

It's a long read. For those who click through, Thomas's opinion starts after the 40-page majority opinion, and is also very long. He quotes Thomas Sowell, though, among many others. And disses Sotomayor very thoroughly.