Laura Adams, senior analyst at insuranceQuotes.com, said the nearly even split means that the question of whether Obamacare affects the election — and which candidate it ends up helping — "may come down to who really gets out to the polls."
Adams noted that younger adults, known as millennials, are the group most likely to support the ACA, and to say that their health insurance situation is better today than it was a year ago. A total of 54 percent of millennials want to keep the law, as opposed to 32 percent who favor repeal.
"If they show up, they could influence" the outcome of the race, Adams said.
On the other hand, she said, adults age 50 to 64 were the group most likely to favor repealing Obamacare, and to say their insurance situation has worsened over the past year. Half of the respondents in that age group favor repeal, while 42 percent favor keeping the law intact.
The survey also showed the persistence of a a wide partisan split on the issue. A total of 74 percent of self-identified Democrats favored keeping the law, which was proposed by a Democratic president. And 77 percent of Republicans want the law repealed.
The overall findings mean that "health care will certainly be a hot-button issue during the 2016," Adams said. "Positive and negative emotions are still strong five years after the Affordable Care Act was passed, and two years after the initial enrollment period."