"Job Creation"

So, hey, why is everyone on Obama and Romney's cases about their records on job creation?  I don't know about how they do things in Massachusetts, but last I checked the creation of jobs and management of the economy wasn't one of the enumerated powers of the federal executive office.  Isn't that a bit like citing a schoolteacher for their poor record on prosecuting violent felons or closing potholes?  Where is it in the job description?