The president has very little control over the economy. It makes much more sense to vote based upon foreign policy and social issues. The economy will do what it does, pretty much regardless of who gets elected in 2012.
If the president has little control over the economy, then what was the purpose of that $800 billion "stimulus" package? Presidents can take actions that have a dramatic impact on the economy. For example, broad based tax reform. They can also take actions that have a dramatic effect on our fiscal solvency, which ties directly into the economy.
It makes almost no sense to vote based on social issues, since Presidents have extremely little impact in that area. The one big exception is judicial appointments. However, the vast majority of social issues (abortion and gay marriage come to mind) are, or should be, left to the states.
I agree with you on foreign policy, which continues to be an important issue, right up there with the economy.