The 1st District Appellate Court’s longest-serving justice has ended his membership in The Chicago Bar Association, citing frustration with how the bar group handled a negative rating of a Cook County judge in this month’s election. Justice Thomas E. Hoffman, in a letter sent to the CBA on Wednesday, took issue with the CBA Judicial Evaluation Committee’s recommendation to vote against retaining Circuit Judge Thomas E. Flanagan of the Law Division. Among 73 candidates for judicial retention on the …