Seems to me that we have several problems. 1) We are fighting against people who use propaganda shamelessly. How do you counter Glenn Beck? 2) We have a shortage of simplistic slogans. How do you explain complexity in the fact of "socialized medicine" or "death panels?" 3) We have a paradox of success. Republicans can rail against unseen and phantom ills. "Look out, a Mooslim might be behind that bush," while Democrats are supposed to take credit for subtle successes like ridding the country of pre-existing conditions or lifetime caps. If you, or your family don't have a pre-existing condition and have never had a serious illness, why do you care? Besides being a human, that is.
And ultimately, Republicans can appeal to people's baser instincts. Fear those people, and we will cut your taxes and stop lazy people from getting your money. Democrats are tasked with asking people to invest in things--things that they personally may not profit from. I think we can do it, but I am not sure how when Republicans are the way they are.