Who is every vacator with reason for change as resigned December 31, 1959?
CREATE TABLE "table1_2159571_2" (
  "district" text,
  "vacator" text,
  "reason_for_change" text,
  "successor" text,
  "date_successor_seated" text
);
SELECT "vacator" FROM "table1_2159571_2" WHERE "reason_for_change"='Resigned December 31, 1959';