More than 7 in 10 say the law will fully go into effect with some changes, ranging from minor to major alterations, a new Associated Press-GfK poll finds.
Only 12 percent expect the Affordable Care Act — "Obamacare" to dismissive opponents — to be repealed completely.
The law — covering 30 million uninsured, requiring virtually every legal U.S. resident to carry health insurance and forbidding insurers from turning away the sick — remains as contentious as the day it passed more than two years ago. There's still more than another year before its major provisions go into effect on Jan. 1, 2014.
Although the overhaul survived a Supreme Court challenge in June, the November election appears likely to settle its fate. Republican Mitt Romney vows to begin repealing it on Day One while Obama pledges to carry it out faithfully.
But the poll found that Americans are converging on the idea that the overhaul will be part of their lives, although probably not down to its last comma. They don't totally buy what either candidate is saying.
"People are sort of averaging out the candidates' positions," said Harvard School of Public Health professor Robert Blendon, who tracks polling on health care issues.
Forty-one percent said they expect the law to be fully implemented with minor changes, while 31 percent said they expect to see it take effect with major changes. Only 11 percent said they think it will be implemented as passed.
Americans also prefer that states have a strong say in carrying out the overhaul.
Sixty-three percent want states to run new health insurance markets called "exchanges." Open for business in 2014, exchanges would sign up individuals and small businesses for taxpayer-subsidized private coverage. With GOP governors still on the sidelines, the federal government may wind up operating the exchanges in half or more of the states, an outcome only 32 percent of Americans want to see, according to the poll.
Developed with researchers from Stanford University and the University of Michigan, the poll also found an enduring generation gap, with people 65 and older most likely to oppose the bill and those younger than 45 less likely to be against it.
Republicans remain overwhelmingly opposed to the overhaul and in favor of repeal. But only 21 percent said they think that will actually come about.
Romney supporter Toni Gardner, 69, a retired school system nurse from Louisville, Ky., said that until a few weeks ago she was sure her candidate fully supported repeal, as she does.
But then Romney said in an interview there are a number of things he likes in the law that he would put into practice, including making sure that people with pre-existing medical problems can get coverage. The Romney campaign quickly qualified that, but the candidate's statement still resonates.
"If Romney gets in, he'll go with parts of it," Gardner said, "and there are parts of that he won't go with."
Gardner thinks expanding coverage will cost too much and may make it harder to get an appointment with a doctor. Besides, she doesn't believe the government can handle the job. She's covered by Medicare — a government-run health system — but says "that wasn't a choice that I had."
At 26, Santa Monica, Calif., web developer Vyki Englert has only bare-bones health insurance coverage. Her parents, a preschool teacher and a self-employed photographer, are uninsured. Englert says she thinks the law will largely go into effect as passed. (Among 18- to 29-year-olds, 60 percent think it will be implemented with only minor changes or none at all.)
Englert says that she supports guaranteeing coverage to people with health problems and that provisions such as broader coverage for birth control will help younger women such as her.
"I kind of see a day-to-day way where this law could benefit me," she said. Englert says the health care law dovetails with a trend toward consumerism in her generation. Older Americans "don't have the context of the young people," she added. "They are looking more at the theoretical impact on the budget and the country."
Overall, the poll found Americans divided on repeal, with neither side able to claim a majority. Forty-nine percent said the health care law should be repealed completely, while 44 percent said it should be implemented as written.
The notion that the law will be implemented with changes, captured in the poll, mirrors a discussion behind the scenes in Washington, particularly among some Republicans.
"Whoever wins the election, the (health care law) is going to be modified," Mark McClellan, who ran Medicare under former President George W. Bush, said in a recent interview.
Congressional Republicans say if tax increases are on the table in budget negotiations with a re-elected Obama, changes to the health care law or delays in implementation are also fair game.
Some parts of the law already are in effect; its big push to cover the uninsured doesn't come until 2014.
Public opinion about the law itself has barely budged since 2010, soon after it passed. At the time, 30 percent supported it. That's now 32 percent. And 40 percent opposed the overhaul. That's now 36 percent.
Misconceptions about the law that reigned two years ago live on, including former Alaska Gov. Sarah Palin's widely debunked charge that it would create "death panels" to decide on care for the elderly and disabled. In 2010, 39 percent believed the law would set up committees to review individual medical records and decide who gets care paid for by the government. Forty-one percent still hold that view, according to the poll.
The poll asked people to say whether 18 different items were in the law or not and to rate how certain they were about their answers. Just 14 percent were right most of the time and sure of it.
Still, knowledge about what the law actually does is growing. More people are aware of provisions that allow adult children to stay on their parents' coverage until age 26, impose insurance mandates on individuals and businesses, and protect those with pre-existing medical conditions.
The poll was conducted Aug. 3-13 and involved interviews with 1,334 randomly chosen adults nationwide. It has a margin of sampling error of plus or minus 3.4 percentage points.
The survey was conducted online by GfK using its KnowledgePanel sample, which first chose people for the study using randomly generated telephone numbers and home addresses. Once people were selected to participate, they were interviewed online. Participants without Internet access were provided it for free.
AP News Survey Specialist Dennis Junius contributed to this report.