The ACA was originally conceived as a "three legged stool." Folks weren't able to get health insurance because of pre-existing conditions. So we said, let's get rid of that, and require health insurers to take everyone and limit their ability to do experience rating. But health insurers objected, saying it would result in adverse selection - folks would wait until they got sick before buying health insurance. That would lead to insurance companies going bankrupt (although if you're a hard core single payer shipper, then you might want that, even if people get hurt along the way - that can be discussed elsewhere; let me finish my thought). So to address that problem we decided to require everyone to buy health insurance or face a financial penalty. But some people might have trouble affording either insurance or the penalty - so we added financial assistance for people who couldn't afford it. These three elements together became the three legged stool:
Guaranteed issue
Individual mandate
Subsidies
Of the three, it was inevitable that #2 would be contentious. People don't like being told what to do. It was challenged and it went all the way to SCOTUS, who decided that the individual mandate fell within Congress's power to tax. So we all breathed a sigh of relief.
Then under Trump - before the pandemic - Congress zeroed out the penalty. Technically the mandate remains in place - but it's essentially neutered. What this shows is that the issue was never a Constitutional one - it was always political. People hate being told what to do.
Then under Biden we tried a different tack. Taking advantage of the Covid crisis, they dramatically increased the subsidies. Suddenly more people were eligible. Who needs the stick, if you just offer a really, really big carrot?
And then Trump came back. The expanded subsidies went away, and the mandate penalty was zeroed out permanently.
What could have been done differently here?
Consider Australia. In the early 2000's they came up with a different solution for adverse selection. You can opt out of buying private health insurance, but if you wait, the insurance company gets to tack on an extra 2% to your premium for each year you waited. That extra amount is called the *loading* fee, and it stays with you for ten years. And it's not tax deductible.
In my opinion, we missed the opportunity to synthesize something similar here under Biden. At the same time that the expanded premium tax credits were introduced, we should have added the penalty back, but with a twist: instead of making it a real debt obligation to the government, it should have been an *offset* to the subsidy. So the "penalty" would just be a smaller subsidy, based on how long you waited to get health insurance. The "phantom penalty" would accrue interest, same as any other "real" penalty. But you'd never owe the government anything. Wanna raw dog it and never buy health insurance? Fine, but if you wait, your subsidy is going to be a lot smaller for a while. Basically, I'm proposing that we fuse legs 2 and 3 of the stool, to solve the adverse selection issue in a way that nobody can say is coercive.
The other thing we need is a public option. Again, adverse selection is an issue. So we do what Medicare already does - and have a penalty tacked on to the premium for every year you wait after you become eligible. The concept is the same whether you become eligible at 65 or 25.
Finally, we can tweak existing systems to create something with the same look and feel as single payer, from the provider's perspective - extend Medicare crossover claims, conditional payments and recoveries to everyone, even folks who don't have and aren't even eligible for Medicare. Medicare would front the payment for everyone, but if it turns out you've got your own health insurance, they'd recover it on the back end. Think of this as "single biller" health care. If you don't have health insurance, fine - Medicare recovers it from you directly, with safeguards for financial hardship. Many states allow for "spend-down" for Medicaid eligibility - in some cases they allow people to make deposits with the city or county. This could also be integrated.
I'd like to add a few more things, like allowing people to service student debt as an offset to the subsidy - but I'd start with the above things. We need a durable fix that we can all accept.