"You can't "fix" something when one side treats it as untouchable and uses it as a campaign prop instead of a policy."
You literally believe you're talking about Dems, and in reality, you're talking about Republicans. When amongst themselves at the Heritage Institute, Republicans could never come up with a plan that didn't include a mandate. Once Obama copied the HF Plan, Republicans disowned it.
Then, whenever an error or weakness would be found, no Republican EVER voted to fix it, for fear they'd be primaried for "supporting" Obamacare. (Contrast that to the R's eff-up with the tax code and farmers, which the Dems voted to correct immediately.)
Ultimately, Republicans always failed to repeal Obamacare, especially as more voters realized that WAS the Affordable Care Act. And, of course, because they've never had even the concept of a plan.
But everyone who's ever been to a committee meeting about the numbers knows it doesn't work without a mandate. Republicans effectively repealed Obamacare when they eliminated the mandate. They own this new plan.
What sounds better: TrumpCare, or The Unaffordable Care Act...?
One more very important thing about the ACA:
Back in the 80s, no one had ever heard the phrase "pre-existing conditions". By 2008, that phrase was everywhere, and the baby boomers (virtually all with PECs) were just about to be tossed into high-risk pools, which were charging about 10X the COBRA rate at that time.
FTW, COBRA is made available to insured folks for ~18 months after termination, but because a) it takes all comers, and b) folks who know they'll need it are more likely to opt for it...the price is roughly the same as for a 64 yr old man, i.e., the top rate of the market. But while that was roughly $500-$600/mo in the year before the ACA, the high risk pools were charging roughly $5000-$6000/mo.