The problem is that the Conservatives have no idea what health insurance is, what insurance companies actually do, and how they relate to health care delivery. If they did, they'd see that insurance companies are completely extraneous to this and serve no purpose when it comes to health care.
Nope... It's morons who yammer about covering pre-existing conditions who don't know what the fuck "insurance" is. It's the same idiots who don't comprehend that forcing everyone to purchase an all-inclusive, one size fits all healthcare insurance policy doesn't lower the cost of health care or make it more available.
Conservatives realize the best solution for most Americans is a patient-centric market based system and that we already have a solution for the poor and elderly, called Medicaid and Medicare.