Supreme Court Justices Antonin Scalia and Clarence Thomas raised eyebrows and ethics questions late last year when they attended a conference sponsored by Charles and David Koch, the billionaire brothers who head Koch Industries. A comprehensive expose from The New Yorker reported on the Koch Brother’s immense financial and ideological ties to right-wing and pro-corporate groups, and the Koch-sponsored event that Scalia and Thomas attended was held “to review strategies for combating the multitude of public policies that threaten to destroy America as we know it.” The Koch Brothers have greatly benefited from the Supreme Court’s pro-corporate rulings, including the Citizens United decision which allowed corporations to use funds from their general treasuries to finance, sometimes secretly, political organizations. Tomorrow is the first anniversary of Citizens United, and Common Cause is requesting that the Justice Department look into whether Justices Scalia and Thomas should have recused themselves from the case:

The government reform advocacy group Common Cause today asked the Justice Department to investigate whether Supreme Court Justices Clarence Thomas and Antonin Scalia should have recused themselves from the landmark Citizens United vs. Federal Election Commission decision because they were involved with an array of conservative groups that stood to benefit from it.

In the case, the Supreme Court by a 5-4 margin struck down a provision of the McCain-Feingold campaign finance act that prevented corporations and unions from spending an unlimited amount of money on electioneering, such as campaign ads. Scalia and Thomas sided with the majority in the decision, which was made a year ago this week.

In a letter addressed to Attorney General Eric Holder, Common Cause President Bob Edgar said both justices should have been disqualified from hearing the case because of their ties to Charles and David Koch, wealthy brothers who fund an array of conservative causes.

The justices both attended “retreats” held by Koch Industries, Edgar said, that focused on championing conservative ideas including opposition to campaign finance laws.

Their attendance raises the question of whether the two judges were impartial in their decision, Edgar said. He also questioned Thomas’s impartiality because his wife, Ginny, ran a nonprofit group that Edgar said benefited greatly from the Citizens United decision.

“Until these questions are resolved, public debate over the allegations of bias and conflicts of interest will serve to undermine the legitimacy of the Citizens United decision,” Edgar said.