Shifting the cost of healthcare from private to public funding is not as easy as simply enacting law at the state level. States don't have the power to create money in the private sector for the common welfare as the federal government does. While it may be cost effective to use tax revenues to fund general healthcare there are other considerations that can be problematic.
The insurance industry has established its own economy via its complexity and its propensity to withhold payment if all conditions aren't met. The result has been the adoption of a great number of non-medical workers who do nothing but satisfy those conditions for providers. There is also a significant number of people who derive all, or a considerable portion, of their income from insurance sales and administration within the insurance industry.
Not all of those workers are going to be quickly absorbed into the workforce and it would be unfair to them to not provide retraining and support while transitioning. That transition may require years for some and others may step right into the healthcare jobs such a move would open up. However, simply comparing numbers from premiums and direct healthcare costs would be a mistake. For states, not being able to fund deflationary events such as this would be, the challenge is much more difficult than it is for the federal government which creates the currency on demand.