Final answer:
Amendment 17 allows a governor to call a special election to fill a vacant Senate seat, and with state legislature authorization, the governor may appoint a temporary replacement until the election.
Step-by-step explanation:
According to Amendment 17 of the United States Constitution, if a senator dies or otherwise leaves office before their term has ended, the governor of the respective state is required to set the time for a special election to fill the vacancy. However, the state legislature may empower the governor to temporarily appoint a replacement until the special election can be held. This temporary appointment ensures that the state continues to have representation in the Senate until the people elect a new senator.
The process of senatorial elections provides that the Senate is a continuous body, with only about one-third of the seats up for election every two years. Originally, senators were selected by state legislatures, but the 17th Amendment, ratified in 1913, shifted this power to the people, allowing for the direct popular election of senators.