This is very apt. It does not matter which party is in government, a country's prosperity depends on the state of the economy. Lets face it, a country's economy today is much more influenced how the central bankers manage the economy and teh state of the global economy. Look at Britain, Tony Blair was fortunate to be in power while the economy was doing well. Gordon Brown's firtunes have taken a battering due to the depressed state of UK economy over the last couple years.
The economy is cyclic and it will have ups and downs. If it goes up the leader looks great, if it goes down, they look like a failure. It is common but people still do not see trends.