When rudolph kleberg (d) is the successor is the reason for vacancy?
CREATE TABLE "table1_2417445_4" (
  "district" text,
  "vacator" text,
  "reason_for_vacancy" text,
  "successor" text,
  "date_of_successors_taking_office" text
);
SELECT "reason_for_vacancy" FROM "table1_2417445_4" WHERE "successor"='Rudolph Kleberg (D)';