Twenty House Democrats on Thursday asked for a federal investigation into Supreme Court Justice Clarence Thomas' failure to disclose his wife's income, charging that he may have violated the court's ethics rules.

Supreme Court Justice Clarence Thomas failed to report his wife's income from a conservative think tank on financial disclosure forms for at least five years, the watchdog group Common Cause said. Between 2003 and 2007, Virginia Thomas, a longtime conservative activist, earned $686,589 from the Heritage Foundation, according to a Common Cause review of the foundation's IRS records. Thomas failed to note the income in his Supreme Court financial disclosure forms for those years, instead checking a box labeled "none" where...

NPR's Supreme Court correspondent Nina Totenberg received a leaked Judiciary Committee/FBI report that a former colleague of Thomas, University of Oklahoma law school professor Anita Hill, accused him of making unwelcome sexual comments to her when the two worked together at the Department of Education and EEOC. On October 11, 1991, Hill was called to testify during the hearing. She sought to emphasize the inappropriate nature of the alleged behavior, rather than focusing on whether it was illegal or not, but said that in h...