CREATE TABLE table_59816 ("Member" TEXT, "Party" TEXT, "Electorate" TEXT, "State" TEXT, "Term of office" TEXT)

What party has a term of office of 1951 1966, and a State of sa?
SELECT "Party" FROM table_59816 WHERE "Term of office" = '1951–1966' AND "State" = 'sa'
SELECT "Party" FROM "table_59816" WHERE "State" = 'sa' AND "Term of office" = '1951–1966'