From personal experience, our family has learned that a government-run insurance plan is essential to keep insurance companies honest. Our son has special needs but works two jobs. Of course, neither of the jobs provide health care, so we're currently forced into the "for profit" private market for health care and insurance.
It took much research and confusion, but we found what appeared to be a decent plan for a healthy single young man. After several routine doctor visits, including one for an ear infection, we discovered this plan from a major insurer did not cover any of his visits, tests or prescriptions, plus it has significantly increased his policy rate twice already, in two years.
Outside competition is necessary to keep the insurance companies honest. I received excellent government-run health coverage while I was in the Navy, and our government can best provide -- and should provide -- honest coverage for those who need it most.