The Affordable Care Act (disparagingly called Obama Care) is not an insurance program it is in part an exchange (website) where at people with lower income and no employer provided insurance can buy it. The insurance is identical to that sold by the same insurance companies outside the exchange. The premium is subsidized based upon income of the applicant. It works extremely well and has improved the situation for millions of Americans, including ourselves. The early snag was the unwillingness of some insurance providers to participate as the negotiated premiums cut into their profit.
The ACA also has imposed new rules on the insurance providers, no longer can they drop sick people's coverage or deny coverage. Myself, with a history of cancer I would be uninsurable under the old system, or I could get a terrifically expensive policy that would deny coverage for anything they could relate to the cancer. Some years ago my friend got skin cancer and she was denied coverage because she had seen a doctor for acne as a teen. The ACA is not ideal as it still allows insurance companies to continue to disregard doctor direction (they today have taken ownership the majority of clinics and hospitals to enable them to dictate care).
The stone-cold fact that must be addressed is that you cannot make money insuring sick and elderly people, it can't be done. The government has, as a consequence, needed to intervene and require them to cover these folks if they wanted to sell insurance in America. To make the system work well, everyone (universal) needed to be insured, thereby sharing the costs. Republicans successfully fought to remove the 'universal' care aspect hoping to bankrupt the system. Instead, because millions now had coverage they could never afford otherwise, it shifted the costs of the premium subsidies to the taxpayers. Now when an uninsured young person or whoever, requires care (emergency room) they cannot be denied care (Emergency Medical Treatment and Active Labor Act of 1986) but in the end often must resort to writing off the bill (and adding the costs to insured patients) or suing for payments that will bankrupt most people.
In effect we already have universal healthcare, just really expensive, bloated with profiteering and inefficient due to multiplicity of actors.