The public interest group Common Cause today announced that it has asked the Justice Department to investigate whether Supreme Court Justices Antonin Scalia and Clarence Thomas should have recused in last year’s Citizens United case because of their alleged ties to Koch Industries, a company described as a “major beneficiary” of the ruling.

The privately held company, whose owners Charles and David Koch have funded conservative organizations, holds private conferences with business and political leaders and commentators to strategize about countering “the most critical threats to our free society,” according to one brochure revealed last year at the Think Progress Web site.

The brochure, which was promoting this year’s conference scheduled for next week, boasted that Scalia and Thomas had attended prior retreats. Today, Common Cause lawyer Arn Pearson said research has revealed that Scalia attended a 2007 Koch conference and Thomas went in 2008, both apparently in the Palm Springs, California area. Pearson said the justices’ financial disclosure reports for those years did not disclose any travel or lodging reimbursements by Koch. But both Scalia and Thomas indicated they were reimbursed for trips to California by the conservative Federalist Society around the dates when the Koch retreats may have occurred, Pearson stated.

Indeed, Scalia in 2008 reported that the Federalist Society reimbursed him for a Jan. 29, 2007 speech in Indian Wells, California. and Thomas in 2009 reported Federalist Society reimbursement for a Jan. 28-29, 2008 speech in Palm Springs.

In a telephone conference call today, Pearson said Common Cause is not seeking a criminal probe, but rather a “fact-finding investigation” to determine if the justices should have recused under 28 U.S.C. 455, which governs recusals by federal judges. If the department determines that a recusal was necessary, Pearson said the Justice Department, which was in effect a party to the Citizens United case, should move for their recusal, even though the decision is a year old. Because the justices did not disclose their conflicts at the time, Pearson reasoned, “there was no opportunity” for parties to seek their recusal before the decision. Common Cause’s letter to Attorney General Eric Holder Jr. is here.

The letter draws a connection between Koch Industries, other corporate attendees and the Citizens United decision because the ruling enabled those attendees to make unlimited expenditures in federal campaigns. That is unlikely to suffice as proof of a direct conflict of interest, but Common Cause invoked the part of the recusal law that requires judges to step aisde when their impartiality “might reasonably be questioned.”

In its letter to Holder, Common Cause also zeroed in on the involvement of Justice Thomas’s wife Virginia, whose conservative organization Liberty Central took funds from corporate donors who benefited from Citizens United and allegedly also had ties to Koch Industries. Late last year Virginia Thomas withdrew from a leadership role in the organization, and her current role is uncertain. According to its Web site, Liberty Central’s current chief operating officer and general counsel Sarah Field formerly worked at the Charles G. Koch Charitable Foundation.

Stanford Law School professor Deborah Rhode and George Washington University Law School professor Jonathan Turley also joined the conference call to point out that the Common Cause charges highlight the lack of ethics enforcement when it comes to the Supreme Court. Recusal motions, on the rare occasions when they are filed, go to the justices themselves and their decisions are not reviewed by the full Court or anyone else. “The rules are left to the accused,” said Turley. “They become their own judges.” Said Rhode, “There is almost no meaningful oversight of recusal decisions.”