Complex sentence: A highly affluent and predominantly urban state with an ethnically diverse population, New Jersey has become a reliably blue state, and this was evident again when Democrat Barack Obama comfortably won the state's 15 electoral votes with 57.14% of the vote.
Split into simpler sentences: A highly affluent and predominantly urban state with an ethnically diverse population, New Jersey has a tendency to lean Democratic. It is, nevertheless, a reliably blue state that was evident when Democrat Barack Obama won the state's 15 electoral votes by with 57% of the vote.