Who was the vacator when the reason for change was failure to elect?
CREATE TABLE "table1_225206_3" (
  "state_class" text,
  "vacator" text,
  "reason_for_change" text,
  "successor" text,
  "date_of_successors_formal_installation" text
);
SELECT "vacator" FROM "table1_225206_3" WHERE "reason_for_change"='Failure to elect';