... Scalia has steadfastly argued that his constitutional methodology immunizes him against accusations of religious bias. He is a religious man, yes. But he has a shield: his adherence as an appeals-court judge and then a Supreme Court justice to a mechanical interpretive approach, rooted in textualism and original public understanding. Scalia reads the Constitution attending only to the words on the paper. He derives their meaning not from his own values and preferences, he insists, but from the historically grounded meaning of the document’s authors. What he personally believes as a judge is thus immaterial; his religion never enters into his decision-making process.

[In Scalia: A Court of One, Bruce Allen] Murphy carefully lays out the flaws in Scalia’s claim that simply channeling history is a neutral enterprise. Scalia vaunts his departures from Church doctrine, as evidenced, for instance, in a 2002 vote in favor of capital punishment—a stand at odds with Pope John Paul II’s opposition to the death penalty in “Evangelium Vitae.” Writing in the journal First Things, Scalia cited that position as proof that legal rules alone guide him. Yet what really goaded him, Murphy persuasively argues, was that the pope shifted his position on capital punishment, just as proponents of living constitutionalism have done at the Supreme Court. This is not, in Murphy’s view, a value-neutral position. Whether Scalia acknowledges it publicly or not, he is channeling a fundamentalist reading of the Bible—Leviticus in particular.

Scalia’s religious self-certainty, Murphy concludes, has had a practical effect as well as a jurisprudential one. It has, over the decades, isolated him on the Court and eroded his influence among the other justices. The man who arrived on the Court in 1986, as Murphy recounts, was amply endowed with charm and powers of persuasion. He had plenty of experience as a negotiator and a compromiser—all deployed to good effect during his stints in various government agencies in the Nixon and Ford administrations. But once he was ensconced among the chosen few, a dogmatic (Murphy would say quasi-religious) need to be right became his guide. Rather than operate as an effective coalition builder, Scalia emerged as an Old Testament–style Jeremiah, often hollering alone in the wilderness...