CREATE TABLE table_18333 ("District" CLOB, "Incumbent" CLOB, "Party" CLOB, "First elected" FLOAT, "Result" CLOB, "Candidates" CLOB)

What party was the winning one in the elections in the California 30 district?
SELECT "Party" FROM table_18333 WHERE "District" = 'California 30'
SELECT "Party" FROM "table_18333" WHERE "District" = 'California 30'