If a senator resigns, the process for filling the vacancy depends on the state. In most states, governors have the power to appoint a temporary replacement until a successor is elected to fill out the rest of the term. In some states, the governor must choose from a list of nominees submitted by the previous senators party. If the vacancy falls late in the term, the seat is filled at the regularly scheduled general election.
A senator can resign by writing a letter of resignation to the governor of the state that the senator represents. Under the Constitution of the United States and the Seventeenth Amendment, in case of a vacancy in the Senate resulting from resignation, the executive authority of the state (today known in every state as the governor) can make a temporary appointment to fill the vacancy if so authorized by the state legislature. A special election may follow depending on timing and state law.
For a vacancy in the office of United States senator, the governor shall appoint a person to fill the vacancy. That appointee shall be of the same political party as the person vacating the office and, except as provided in subsection D of this section, shall serve until the person elected at the next general election is qualified and assumes office. If a vacancy in the office of United States senator occurs more than one hundred fifty days before the next regular primary election date, the person who is appointed pursuant to subsection C of this section shall continue to serve until the vacancy is filled at the next general election.
