A group of House Democrats, led by Rep. Louise Slaughter, on Thursday called for an investigation into Supreme Court Justice Clarence Thomas’ alleged failure to disclose his wife’s income in violation of the court’s ethics rules.

In a letter to the Judicial Conference, which is responsible for overseeing judicial practices, the 20 lawmakers citing a law that requires all federal judges to disclose spousal income charge that throughout his tenure on the Supreme Court, Thomas has checked “none” on his annual financial disclosure forms. They point to the fact that his wife, Virginia Thomas, earned close to $700,000 from the conservative Heritage Foundation from 2003-2007 as an example.  

The group of lawmakers, which includes Congressional Black Caucus members John Conyers, Donna Edwards, Keith Ellison, Jesse Jackson, Jr., and Gwen Moore, also cite a New York Times investigation that found Thomas may have benefitted from the use of a privately-owned yacht and airplane, but did not disclose the travel as a gift or travel reimbursement.

“Due to the simplicity of the disclosure requirements, along with Justice Thomas’ high level of legal training and experience, it is reasonable to infer that his failure to disclose his wife’s income for two decades was willful, and the Judicial Conference has a non-discretionary duty to refer this case to the Department of Justice,” the lawmakers wrote.

“Particularly as questions surrounding the integrity and fairness of the Supreme Court continue to grow, it is vital that the Judicial Conference actively pursue any suspicious actions by Supreme Court justices,” they added.

In a separate press release, Slaughter notes that the Heritage Foundation was “a prominent opponent of the Affordable Care Act, an issue that is expected to be considered by the Supreme Court in the near future.” Earlier this week the Department of Justice asked the court to review an appeal court’s ruling that the legislation’s individual mandate is unconstitutional.

Last year, during her confirmation hearings, Obama nominee Elena Kagan, who ultimately was confirmed, faced questions from Republicans about her impartiality because she was the White House’s solicitor general when the legislation was being drafted. 

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