The city of Houston has a strong mayoral form of municipal government. Houston is a home rule city and all municipal elections in the state of Texas are nonpartisan. The City's elected officials are the mayor, city controller and 16 members of the Houston City Council. The current mayor of Houston is Sylvester Turner, a Democrat elected on a nonpartisan ballot. Houston's mayor serves as the city's chief administrator, executive officer, and official representative, and is responsible for the general management of the city and for seeing that all laws and ordinances are enforced.
 What does Houston's senator also serve as?