And this will be different how?
Seriously though, (I can be serious) Obamacare is more "unpopular" than anyone could have predicted. I wonder why that is. Have the Republicans oversold the idea that it's pure evil and are now wondering what they can do to contain all the people that were stupid enough to believe them? It's like the debt ceiling fight(s). Are the politicians surprised at all when the people believe the things they say about it (license to create a spending free-for-all, etc)? Or are the reps just as dumb as the rednecks?
A combination of things.
1) Obama stupidly underestimated the opposition. He does this on a regular basis. When you let your opponents define you or a policy of yours, and just expect the press/public/etc to sort out the truth for you, you're screwed. This is called Democratitist, a syndrome that affects party leaders from time to time. John Kerry getting Swiftboated comes to mind as well. Not sure why this keeps happening, but I suspect its that the Dems put too much trust in the abilities of the lamestream media, not realizing that Edward R Murrow has been dead for a long, long time.
2) You make money on the right by throwing bombs instead of reasoned opposition. Sarah Palin is widely thought of as a buffoon. Sarah Palin is now a millionaire. Think Ted Cruz, Mike Lee, Michelle Bachmann, etc don't see themselves doing that? Why bother with K Street, where you might actually have to do some work and even worse do it anonymously when you can make more money with a gig on right wing media? Since there's no down side from being wrong, pols and pundits are free to launch any ridiculous attack they want. Maybe one of them turns out to be correct, who knows? But in the meantime, if you do it well and incite rage, start lining your pockets because you're about to get really wealthy really quickly.
3) Its tough to do big things anymore. People have little trust in govt, the church, business, etc and there's too much contradictory info. People don't like Obamacare because they're confused about it, but they also don't like the opposition. So, what DO people like? Who knows, except maybe to complain. Until the country picks itself up from the economic dolldrums this kind of skepticism is going to be the norm during off election years. Oddly enough, people tend to get optimistic during election years, something the GOP hasn't figured out since Reagan. They can't understand why warnings of the apocalypse aren't driving voters to the polls.
4) Lastly, its taken too long to implement. A fair point is Medicare came on line quickly in the mid 60's after the bill was passed. I'm assuming SoS too. Like Dodd-Frank, the O needs to speed up his legislative victories instead of the 10 year phase in process. Hopefully his successors will learn from this glaring mistake.