Right now, almost half of the country is either uninsured or underinsured.
The groups that left the AFL-CIO should use their resources to form a not for profit insurance industry and offer nationalized health care. There have been examples of public ownership in the past and they worked. I believe Robert Hunter directed one of them. This idea was described in a book called the "Invisible Bankers" . There would be several benefits to this: you could solve the healthcare crisis, you could show an immediate positive benefit to union involvement, and you could create a several billion dollar reservoir (60 million spend 50 dollars a month for full healthcare services) that you could use to fund principled investment and to build real political power--for example, replicating America Coming Together, building your own press, etc. Did I mention that you would starve the HMOs? All positives.
One warning: write bylaws that prevent you from actually becoming an evil insurance company!