Our high court now has heard arguments about DOMA, the Defense of Marriage Act that Bill Clinton signed into law. (In a startling admission for a former president, Clinton now recants his decision.) The Supreme Court will unveil its ruling in early summer. In the long wait until a ruling, analysts will examine every influence on the justices. Today, let’s look at one possible influence:

Does religion sway the court?

Before you say “No”—consider what one political scientist has found. The religious composition of the high court is atypical by historical standards. There are no Protestants for the first time in history. Six of the justices are Catholic, when the historical norm has been one (or none).

Religious affiliations may influence high-court votes, especially for Catholic justices, says William Blake, a political scientist. In an article published last year in the Political Research Quarterly, he analyzed the effect of religious affiliation on voting behavior between 1953 and 2007. This span includes both liberal Catholic justices and conservative Catholic justices (and liberal and conservative Protestants justices, and so forth).

Blake analyzed hundreds of voting decisions that covered eleven different issue areas that might be influenced by religious values.

Blake’s conclusion is that “Catholic justices vote in ways that more closely adhere to the teachings of the Catholic Church than non-Catholic justices.” This means, for example, that a Catholic justice tends to take a liberal position on civil rights cases, but a conservative position on abortion.

All told, Blake found that Catholic justices are more likely than non-Catholic justices to take a liberal view on civil rights cases and criminal rights case. Catholic justices are more likely to take a conservative position on abortion cases, Establishment Clause cases (separation of church and state), and obscenity cases.

Blake emphasizes that the influence of religion is not conscious. Justices strive mightily to remain impartial. But even Supreme Court justices are human and their religious values can creep into their decisions.

Are you surprised by Blake’s findings?

How do you think religion will influence the ruling of marriage?

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