Lay off the kool-aid
Watch, I can quote half of your sentences, too!
It may have been a political success
I'm glad we agree. ;)
More seriously: yes, you're right that Obama is not at all popular among people who didn't vote for him. But I don't see that as evidence that "the grass is always greener". Obama is more popular in the UK than the US because his political views are a lot closer to the UK centre than the US one. Conversely, almost no one in the US has even heard of Cameron, so you'd be hard-pressed to say whether he's popular here or not.
I don't need to rehash the failed exchange website launch for you
Change is hard. It works now. No one cares.
but very recent headlines suggest that the Affordable Care Act is turning out to be extremely unaffordable. Health insurance premiums are going to go WAY up next year, as high as 85% in some places.
As high as 85% for one plan in one part of Georgia. And Georgia is a special case, since it effectively opted out of one of the key parts of the ACA. You can't judge the plan's success based on its deployment in a state that is actively working to make sure it fails.
Meanwhile, a survey by the Kaiser Family Foundation suggests that 74% of 2015 marketplace plan enrollees are happy with their plans. That's up from 72% in 2014.
In my mind, an extreme policy failure would be something like the Iraq War. The war cost over a trillion dollars and took the lives of hundreds of thousands of people, including nearly 4,500 Western troops. For all that, we didn't find weapons of mass destruction; we didn't succeed at defeating al-Qaeda (or at least, the branch of it that evolved into ISIS); we didn't succeed at establishing lasting peace or democracy; we didn't succeed in securing the long-term future of our oil imports. 81% of Americans think the war was a mistake, and even Jeb Bush -- brother of the person who started the war -- said that he wouldn't invade Iraq again, given the chance.
The ACA, on the other hand, has managed to provide insurance to over 10 million people who didn't have it before, and by and large, those people are happy with their plans. Calling that an extreme policy failure sounds a bit, well, extreme. :)