The U.S. Court of Appeals for the D.C. Circuit’s ruling that the House can’t sue to compel former White House counsel Donald McGahn’s testimony is raising questions for both Capitol Hill and federal judges about the immediate effect it has on lawmakers’s ability to go to court.

Those issues were underscored Thursday as a federal judge weighed how the ruling applies to a separate House lawsuit seeking President Donald Trump’s federal tax returns. U.S. District Judge Trevor McFadden of the District of Columbia said the McGahn opinion—if it stands—has likely cancelled out the House’s arguments in relation to its subpoena on the tax returns.