Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### 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"