The question I don't see getting answered from the aspect of the swing voter is "How does the Republican platform/policy set help me?"
Democrats can point to various policies (college tuition help, subsidized health care, a cleaner environment) that can have some tangible benefits, while most of the Republican benefits are indirectly impacting folks. Smaller government will mean smaller taxes and more take-home pay, not to mention more jobs if the economy responds to it.
However, no president is in a position to offer you a job personally, assuming that you are Joe Average Citizen who isn't going to get a patronage job in the next administration. Democrats can try to put money into supporting types of jobs and Republicans can work on the assumption that a lesser-taxed economy will create X million new jobs, but I can't depend upon one of those jobs coming my way.
With Obama, I at least get some subsidized health care coming in 2014. What would Romney's plan do other than get the public sector rolling somewhat? Dow Chemical's never hired me in 30+ years of trying, so are they going to do so now?
Republican economics is a harder sell, since you have to rely on a more abstract aid from a market economy rather than a more concrete set of government programs. You have to make people think that a stronger economy will help them more than the government help the Democrats are pledging.