Justice Clarence Thomas’s new autobiography dredges up his 16-year-old battle with Anita Hill and fulminates against liberal groups, Democratic senators and others who opposed his nomination. The clash with Ms. Hill has grabbed most of the headlines. But his fulminations deserve more attention. The rage he harbors raises questions about whether he can sit as an impartial judge in many of the cases the Supreme Court hears.

When Supreme Court justices write books, which is not often, they tend to write about subjects and in ways that are consistent with the dignity of the court. When he was chief justice, William Rehnquist wrote about the 1876 presidential election; Justice Stephen Breyer’s “Active Liberty” set forth a specific view of the Constitution.

The problem with Justice Thomas’s book, “My Grandfather’s Son,” is that it nurses bitter grudges and throws brickbats at organizations and people who opposed his nomination and might well appear before the court. Some of his targets, like Senator Joseph Biden and Yale Law School, he mentions by name. Others, like the American Civil Liberties Union, are not attacked as directly, but it is not hard to connect the dots.

The level of hostility is striking. He grew up fearing the Ku Klux Klan, he says, but “my worst fears had come to pass not in Georgia, but in Washington, D.C., where I was being pursued not by bigots in white robes but by left-wing zealots draped in flowing sanctimony.”