U.S. District Judge Robert M. Dow Jr. of the Northern District of Illinois is leaving Chicago to work for a higher court.Chief Justice John G. Roberts Jr. of the U.S. Supreme Court announced Monday that Dow will become his counselor on Dec. 5.A chief judge’s counselor, according to 28 U.S.C. Section 677, “shall perform such duties as may be assigned to him by the Chief Justice.” Those duties under Roberts include serving as his chief of staff, a role that will require Dow to work with court officers on courtwide policies …