Controversy follows U.S. Supreme Court Justice Antonin Scalia like Pig Pen's cloud of dirt. You've probably heard that on Monday night, when the justice was speaking at Princeton, a gay student confronted him about his dissent in the 2003 case of Lawrence v. Texas, in which the majority struck down a state law banning same-sex sodomy. Scalia's dissent discussed the legitimate state interest in legislating morality, and warned that the majority's holding called into question "state laws against bigamy, same-sex marriage, adult incest, prostitution, masturbation, adultery, fornication, bestiality, and obscenity." He also called the opinion "the product of a Court, which is the product of a law-profession culture, that has largely signed on to the so-called homosexual agenda, by which I mean the agenda promoted by some homosexual activists directed at eliminating the moral opprobrium that has traditionally attached to homosexual conduct."

In responding to the brave Princeton student, Duncan Hosie, who asked about his comparison of homosexuality to bestiality, Scalia was characteristically unrepentant. "If we cannot have moral feelings against homosexuality, can we have it against murder?" Scalia said, according to the Los Angeles Times. "Can we have it against other things? I don't apologize for the things I raise." (MSNBC did an extended segment on the flap, featuring Hosie and Georgetown University law professor Jonathan Turley.)

It's safe to say that Scalia, an avowed Catholic, is not likely to receive huzzahs at his local Gay Pride march. But does his apparent approval of "the moral opprobrium that has traditionally attached to homosexual conduct" mean that he should not be part of the court that decides the constitutionality of gay marriage?

I put the question to six prominent Supreme Court litigators. They were unanimous: There's no reason whatsoever for Scalia to recuse himself from the gay marriage cases the court has agreed to review. Even George Washington University law professor Alan Morrison agreed -- and he famously earned Scalia's enmity when, as counsel to the Sierra Club in a 2004 case against former vice president Dick Cheney, he moved for the justice's recusal, citing Scalia's duck-hunting trip with Cheney. According to all of the lawyers I talked to, Scalia's dissent in the Lawrence case does not suggest he cannot be impartial in the gay marriage cases. After all, if we were to assume that the justices' prior rulings were grounds for recusal, every justice would be able to hear only one case on any particular issue. That would leave a notably depleted bench for recurring Supreme Court issues like affirmative action and campaign spending, to name just a couple of examples. "You can't recuse somebody because they've expressed prior views in judicial opinions," Morrison said.

To argue otherwise would undermine the authority of the court. As Scalia himself noted in an opinion denying the Sierra Club recusal motion, there's a high cost to the law when any justice steps aside because there's no one to take his or her place. "The court proceeds with eight justices, raising the possibility that, by reason of a tie vote, it will find itself unable to resolve the significant legal issue presented by the case," Scalia wrote. He went on to quote from the Supreme Court's 1993 statement of recusal policy: "We do not think it would serve the public interest to go beyond the requirements of the statute.... Even one unnecessary recusal impairs the functioning of the court."

To be sure, justices do recuse themselves from cases. The federal statute governing judicial recusals, which says judges must recuse when their "impartiality might reasonably be questioned," applies to Supreme Court justices, who regularly step aside when they have a financial interest in the outcome of a case or have been involved in the case in the lower courts. Justice Samuel Alito, for instance, recused himself from hearing the pay-for-delay case in which the court granted certiorari Friday, presumably because he owns stock in a pharmaceutical company. Similarly, it's thought that one of the reasons the court agreed to hear a 2nd Circuit Defense of Marriage Act decision instead of a similar opinion from the 1st Circuit is that Justice Elena Kagan was involved in the 1st Circuit case when she was the solicitor general. The justices' family relationships can also lead to recusals: Reuters recently reported on Justice Stephen Breyer'srecusal in a pair of environmental cases in which his brother, U.S. Senior District Judge Charles Breyer, sat by designation on the 9th Circuit panels that issued the rulings under review. Scalia might have had to recuse himself from hearing cases argued by Gibson, Dunn & Crutcher, where his son Eugene Scalia is a partner, if Eugene hadn't arranged not to share in profits generated from that firm's robust Supreme Court practice.(Former chief justice William Rehnquist's son had a similar arrangement with Goodwin Procter, as Rehnquist disclosed in an opinion denying a motion that he recuse himself in the government's antitrust case against Microsoft.)

But unlike all other federal judges, whose recusal decisions are subject to review, Supreme Court justices have the final word on their own recusal determinations. The court leaves it up to individual justices to decide whether to step down, and those decisions are not reviewed by the Supreme Court as a whole. Perhaps, as a result, it's very rare for justices to recuse themselves simply because of the appearance of partiality. I can think of only one example in recent years: when Scalia stepped aside in the court's consideration of the constitutionality of the Pledge of Allegiance's phrase, "one nation, under God." (As Linda Greenhouse explained in a New York Times piece, Scalia had made public remarks about the case before it reached the Supreme Court.)

The considerable discretion afforded to the justices doesn't sit well with everyone. Morrison, the lawyer who unsuccessfully moved for Scalia's recusal in the Sierra Club case, told me that the Supreme Court should have a "buddy system," in which justices promise not to decide whether to step aside before reviewing recusal with another justice. A large group of law professors has called for even stricter rules. In 2011, they sent a letter to the House and Senate Judiciary Committees, asking Congress to enact "mandatory and enforceable rules" on recusal that would require Supreme Court justices to abide by the Code of Conduct for United States Judges, rather than treat the code as mere guidance. (I called several of the professors to see if the letter had any impact but didn't hear back.) The way things stand, Morrison said, bringing a formal recusal motion is something of a suicide mission, since you're suggesting to the justice that he or she made the wrong call on impartiality. "I still have scars," Morrison told me. "It's a high-risk strategy to move for recusal. If you shoot the king," you'd better kill him."

There's also a good argument, though, that we should leave the Supreme Court recusal system alone. The other five Supreme Court practitioners I spoke to didn't want to be named because they appear regularly at the court. They all said, however, that recusal decisions should be left to individual justices who, after all, have to prove their judicial temperament in bruising confirmation hearings. Otherwise, recusal becomes a point of litigation strategy and politics. That's the surest way to undermine the court's authority. Remember the chatter surrounding last year's healthcare cases at the court? There were recusal arguments from both sides: Opponents of the healthcare law wanted Justice Kagan to step aside because the law was passed when she was in the Obama administration; and supporters of the law demanded the recusal of Justice Clarence Thomas because his wife lobbied against it. For all of the Sturm und Drang, no one actually filed a recusal motion, and the full court decided the law's constitutionality.

Kagan and Thomas ended up voting as everyone expected on the healthcare law, but it was still important that the whole court had a say. Scalia is similarly unlikely to change his mind about homosexuality and states' rights. But that doesn't mean the court's ultimate decision, regardless of which way the ruling goes, will not be stronger for his devil's advocacy.

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