The big problem the Republicans have facing them is that their fickle supporters, the Tea Party, who has shown every indication that they aren't as interested in the GOP as they are in their principles, wants to lower the deficit and the debt. This will not happen unless health care and defense costs are dealt with. According to the CBO, in 2010, 61% of the tax revenue collected went to social security, medicare/medicaid/CHIP, and defense. The favorite whipping boys of the Tea Party like education and foreign aid only take a very tiny percentage of tax revenue.
The Tea Party doesn't want to see defense cut, and the GOP wouldn't cut it even if they did. Many Tea Partiers are elderly, and they won't want medicare cut. They might be OK with medicaid being cut since that's just the lazy poor, but it's unlikely that the GOP is going to try to make any huge cuts to Medicaid. Attacking Obamacare is not going to fix the cost of health care. The elderly Tea Partiers also aren't going to want to see social security messed with. They also don't want to see taxes rise.
It sometimes works to run on voter ignorance, especially when it comes to areas that are more opinion or morality based. But you can't run on a platform of cutting deficit and debt while saying at the same time that you're not going to raise taxes, cut defense, or cut any programs that benefit the retired and elderly. And if 2012 comes around and nothing is done about the deficit or debt, the Tea Party may fracture the Republican party more than it already has. You can count on your stable base or your "issues voters" to follow you no matter what, but the Tea Party definitely gave the impression of following the GOP for now because it was the better of two bad options.
I agree with the basic idea that the financial state of the US is troubling, and that we do need to fix the deficit and debt problems, but just attacking Democratic policies isn't going to do that.