user: Question: What was the result for incumbent Joseph McKenna who was first elected in 1884?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['California 1', 'Vacant', 'Vacant', 'Vacant', 'Democratic gain']
SQL:

assistant: SELECT "Result" FROM "Table" WHERE "First elected" = '1884' AND "Incumbent" = 'Joseph McKenna';