One of the theoretical rationales for an independent central bank is to avoid the socalled 'political electoral cycles' in monetary policy, which is the tendency of governments to lower interest rates or loosen monetary policy before an election and then tightening them afterwards.
Having a central bank with a time horizon that is longer than the electoral cycle should ensure that monetary policy decisions are not  Page 2 of 10  subject to political pressures. In other words, it should avoid the possibility of taking advantage of short-term and temporary positive trade-offs which ultimately lead to longer-term pain.