Would it have survived without the executive order?
Yes, even with the level of congressional meddling we saw last year, I believe it would limp along if implemented as legislated.
Now, with what appears to be a combination of executive, congressional and HHS active interference, I expect the ACA to fail.
As I have said here many times, Washington state followed a similar path twenty years ago. Insurance reform followed by legislative meddling and collapse of the insurance market.
Sad that we cannot learn from our failures, our successes (like RomneyCare) and from the rest of the developed world.