When the ACA passed a minority supported it.
That means a majority didn't. However, that was a meaningless fact, as a lot of people pointed out.
Some didn't think it went far enough. In other words, "Give me something more."
Others thought it went too far. In other words, "Give me something less."
It's why "we should just fix Obamacare" is a fatuous statement. Some want to fix it by rolling back provisions. Some want to fix it by extending them.
One thing that's fairly common, though, is that those getting something don't want to give it up. It's theirs. That means those getting subsidies don't want to give them up; those being told to fork over their income don't want to give it up. That's one reason why proposed but un-implemented benefits in danger of being revoked are billed by their supporters as something that's being taken away. It's even more potent a message if you tell them that what's properly theirs, whatever it is they're getting, is being given to those they already despise.