The answer, of course, is that most Americans have no idea what's in the law. In the Kaiser survey, 57% said they didn't have enough information to know how it would affect them. When they're asked how they feel about specific provisions, however, they're almost always thunderously in favor.
Here are figures from Kaiser's March 2013 poll:
Tax credits for small businesses to buy insurance: 88% in favor.
Closing the Medicare drug benefit doughnut hole: 81% in favor.
Extension of dependent coverage to offspring up to age 26: 76% in favor.
Expanding Medicaid: 71% in favor.
Ban on exclusions for preexisting conditions: 66% in favor.
Employer mandate: 57% in favor.
If you agree with those provisions, congratulations: You love Obamacare. Yet when respondents are asked how they feel about "Obamacare," they're against it.