user: Question: What party was the winning one in the elections in the California 30 district?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result', 'Candidates']
Types: ['text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['California 3', 'John E. Moss', 'Democratic', 1952.0, 'Retired Democratic hold', 'Bob Matsui (D) 53.4% Sandy Smoley (R) 46.6%']
SQL:

assistant: SELECT "Party" FROM "Table" WHERE "District" = 'California 30';