The chief justice of the state Supreme Judicial Court yesterday apologized for a joke she made at the beginning of her commencement speech at Brandeis University in May, when she quipped to spectators gathered beneath blue and white balloons, ''No red states here." The remark by Chief Justice Margaret H. Marshall, who wrote the court's landmark 2003 decision allowing same-sex marriage, triggered a confidential complaint to the Commission on Judicial Conduct. The commission released an extraordinary statement yesterday from the state's top jurist, who said she regretted making what might have been construed as a political statement. ''The comment was...