(Portland, OR)  --  Portland Police Association President Brian Huntziker is stepping down.  His resignation was announced yesterday after he made what the union says was an isolated but serious mistake related to a hit and run crash that falsely implicated City Commissioner Jo Ann Hardesty earlier this month.  Detectives found the driver involved.  The union's press release did not elaborate on exactly what kind of mistake Huntziker made.  Mayor Ted Wheeler is demanding to know what the mistake was, and he's calling for an internal investigation.