California gained seven seats after the 1990 census, and one of them was the 50th District in south San Diego (renumbered the 51st District after the 2000 census). The district is one of the most ethnically diverse in the nation, including much of San Diego's southern section, the cities of Chula Vista and National City and all of Imperial County. It includes most of California's border with Mexico, except for the city of Imperial Beach. In 1992, Filner ran in a five-way Democratic primary for the seat and won a narrow victory. One of his primary opponents was his former boss, Jim Bates, who had lost his seat in a sexual harassment scandal in 1990 and whose home had been drawn into the district.