 In 1986, Zaffirini defeated the late State Representative William N. "Billy" Hall, Jr., in the Democratic runoff primary for state senator.She then defeated Republican attorney and businessman Bennie Walter Bock of San Antonio in the general election to succeed John Traeger, a Democrat from Seguin in Guadalupe County.From 1973 to 1983, before he switched parties Bock had been a Democratic member of the Texas House from New Braunfels in District 38.