Complex sentence: The party suffered several setbacks since 2001 (when Cito won only 13.9% of the votes in his constituency and failed to be re-elected): between 2003 and 2007, Cito was convicted for Mafia crimes and the party seemed almost completely over.
Split into simpler sentences: The party suffered several setbacks since 2001, when Cito won only 13.9% of the votes in his constituency and failed to be re-elected. Furthermore, between 2003 and 2007, Cito was convicted for Mafia crimes and the party seemed almost completely over.