CREATE TABLE table_18226 ("District" CLOB, "Incumbent" CLOB, "Party" CLOB, "Elected" CLOB, "Status" CLOB, "Opponent" CLOB)

Who are the opponents in district California 9?
SELECT "Opponent" FROM table_18226 WHERE "District" = 'California 9'
SELECT "Opponent" FROM "table_18226" WHERE "District" = 'California 9'