Complex sentence: A bipartisan commission of reformers proposed a new city charter in 1950, which would shift power away from city council to a strong mayor, which they believed would be more efficient and less susceptible to corruption.
Split into simpler sentences: A bipartisan commission of reformers proposed a new city charter in 1950. The new scheme would shift power away from city council to a strong mayor, something they believed would produce a system that would be more efficient and less susceptible to corruption.