Without explanation, the U.S. Supreme Court on Monday abruptly discharged New Orleans lawyer A. Gregory Grimsal as special master in Texas v. New Mexico and Colorado, an original jurisdiction case currently before the court.

Judge Michael J. Melloy of the Eighth Circuit. Courtesy photo.

The unusual order from the court said Grimsal, a member at the firm Gordon Arata Montgomery Barnett, was “hereby discharged with the thanks of the court,” and replaced by Senior Judge Michael Melloy of the U.S. Court of Appeals for the Eighth Circuit.