A federal appeals court in Washington rebuked the U.S. Department of Justice three years ago after its raid on the office of then-Rep. William Jefferson (D-La.). Federal investigators had never before searched a congressman’s office, and the ruling by the U.S. Court of Appeals for the D.C. Circuit declared they should never do so again.

But the court’s decision hasn’t stopped the Justice Department from testing the limits of its powers to investigate Congress. And two ongoing cases present opportunities for the Justice Department to make inroads against the 2007 ruling in Jefferson’s case — a ruling that department officials strongly disagreed with at the time and appealed, unsuccessfully, to the U.S. Supreme Court.