Sixty-nine staff members in the Cook County Public Defender’s Office — 63 of them attorneys — will be laid off in August after the proposed soda tax was put on hold in court.That amounts to almost a 15 percent drop in the number of attorneys who represent defendants who are too poor to afford private counsel, from the current 430 lawyers on staff, according to Public Defender Amy P. Campanelli. This would come on top of the office’s current 50 unfilled attorney positions.“All clients will …