Kate is right that the Arthur Brooks article is interesting, but I would come at it from a different direction. I think that the economic challenge conservatives (to the extent they were embodied in the 2008 Republican field) face is not that they seem to be uninterested in the poor. It is that they seem uninterested in anybody other than the wealthy. Henry Olsen described this perception of Republicans as the people who say that if you give management more leverage and lower taxes, then maybe they won’t close down your factory for a little while longer.
The problem isn’t so much the lack of a an agenda for the poor. It is (as Ramesh Ponnuru had pointed out) the lack of an emphasized agenda for the middle and working-classes. No amount of talk about the free markets and entrepreneurs is going to fix that if the only thing people hear about your actual political program is that you plan to cut taxes on high earners. That message is that the Republicans are offering direct benefits to high earners and are only promising you the miraculous indirect results of lower taxes on Mitt Romney. It should be no surprise if people are skeptical.
Taxes on high earners are a legitimate issue, but non-high earners have their own concerns that need direct policy responses. What if you lose your job and you end up spending several years working a bunch of different part time jobs? you put in more than forty hours a week, but none of those gigs give you health insurance. What do Republicans offer people in that situation? There is an app for that. What if you have a preexisting condition and no health insurance. Conservatives have suggested policy alternatives that are cheaper than Obamacare. Republicans say they are pro-work and pro-family, so why aren’t they out there supporting tax reforms that would improve the work incentives of parents (especially at the lower end of the income scale) while making the tax code more pro-growth?