The Obama camp responded to Hillary today saying that her plan was based largely on the Massachusetts plan and that the failure of some 20% of the state's uninsured to yet enroll is somehow proof a mandate doesn't work. Well, they should fact check their own facts. The deadline for enrollment in the Massachusetts plan is still several weeks off and like anything, lots of people wait until the last minute.
Besides, coming up with some way to compel people to get health care is ultimately the only thing that can make universal coverage work. You can't just have the very sick enrolling in government sponsored plans or the system will go bankrupt. It's like a home insurance company who only insures people who's houses are burning down and tells everyone else they don't have to get home insurance unless they want to. Furthermore, by Obama's own backwards reasoning (see post below) parents only need to be compelled to get health care for their kids, not for themselves.