When was republican incumbent Joseph McKenna first elected?
CREATE TABLE table_name_28 (first_elected VARCHAR, party VARCHAR, incumbent VARCHAR)
SELECT first_elected FROM table_name_28 WHERE party = "republican" AND incumbent = "joseph mckenna"
### Context: CREATE TABLE table_name_28 (first_elected VARCHAR, party VARCHAR, incumbent VARCHAR) ### Question: When was republican incumbent Joseph McKenna first elected? ### Answer: SELECT first_elected FROM table_name_28 WHERE party = "republican" AND incumbent = "joseph mckenna"