If Medicaid were made part of unemployment insurance, it would handle much of the "uninsured" (people no longer covered under prior employer's plan, and who can't afford to pay for COBRA). For people with prior health issues what make them uninsurable (ie, medical expenses would consume over 20% of gross income), also offer them Medicaid.
But that solution would not have the feds taking over a sixth of the economy.
Just one-tenth