Which leads to Justice Rehnquist's important point, made in his response to the meddling senators and lost in the partisan fury over his uppity defense of Scalia: "There is no formal procedure for court review of the decision of a justice in an individual case," he wrote, "because it has long been settled that each justice must decide such a question for himself." This reads like a cop-out, but it reflects a profound truth about the proper limits on the court's powers. The justices are not gods. They do not police one another about matters of conscience for the same reason we should not attempt to police them: No one can know what's in anyone's heart, and in attempting to guess we dredge up only our own fears and biases.
Don't get me wrong. Justice Scalia should step aside in Duckgate, regardless of what's in his heart, because it's a terrible mistake—especially in a landmark case about cronyism and special influence—to allow the appearance of cronyism and special influence to taint what must be a completely fair decision. But it should remain Scalia's decision whether to do so or not. If he cannot be trusted to make it, he cannot be trusted to decide anything.