Let's get real for a moment. The fixing or replacement of the ACA is going to be extraordinarily difficult, and bound to disappoint those in the fever swamps. The reason is the political realities of the age, realities that spawned ObamaCare and doomed it to failure.
Contrary to the folk tale, the ACA is not a nefarious stalking horse for single payer, although there are no doubt those on the left who'd love the chance to replace it with single payor. The temptation is irresistible if you deem health insurance to be a right - if that's the case, then spread its costs among the entire community, preferably in a progressive fashion.
But the reality is that access to health insurance is very arbitrary in this country, and you can blame government policy for that. It depends on whether you have a stable job with a stable employer. And that causes inequities in, literally, matters of life and death, to be equally arbitrary. Lots of hard working folks don't have health insurance.
The ACA has its intellectual origins in 70s-era conservatism. How to address the access issue through a private insurance marketplace without single payer Require everyone to purchase insurance, and the pool will be large enough to sustain a market of guaranteed access insurance for all.
But the political underpinnings of the ACA are all post-Bork partisan warfare. The ACA garnered no GOP support, yet Dem support was near unanimous. So that required the ACA to basically be the bill that was able to satisfy the blue dog Democrats, the most moderate elements of the party that would be willing to sign on. The left essentially compromised with Democratic moderates, leaving a failed mess of the left's costly benefit mandates coupled with the blue dogs' insistence on a private insurance market financed by forced participation by both individuals and employers.
The boot's on the other foot in 2017. Not one Democrat will support any GOP plan to fix or replace ObamaCare. Not one. Tit for tat. We screwed them, they will screw us. No, the only way we are going to be able to fix or replace ObamaCare is to do it the same way the Dems did. The right will need to compromise with what the moderates and libertarians want - the Susan Collinses and the Rand Pauls. The moderates will dictate the result and the right will have to bend. Why? Because it has to be a near-unanimous compromise, or nothing will get done and the failures of the ACA - compounded by the uncertainty - will be laid at the political doorstep of the GOP.