Complex sentence: The party has won gubernatorial races in several states including Chiapas, Michoacán, Zacatecas, Baja California Sur and the Federal District (Mexico City) which has kept since the city was allowed to elect local authorities in 1997.
Split into simpler sentences: The party has won gubernatorial races in several states including Chiapas, Michoacán, Zacatecas, Baja California Sur. It has also maintained control over the Federal District (Mexico City) ever since the city's voters were first allowed to elect local authorities in 1997.