The Rasmussen Reports national telephone survey released Monday also found 49 percent of voters said they strongly favor repeal.
But opposition notwithstanding, only 41 percent predicted the law is even somewhat likely to be repealed, while 45 percent called repeal unlikely.
In the poll, conducted July 1, 36 percent of voters said they oppose repeal, 24 percent strongly.
More than four in 10 said repeal would improve the nation's economy to 27 percent who said it would hurt the economy, while 20 percent said it would have no impact.
Among Republicans, 81 percent said they favored repeal and 56 percent of Democrats said they oppose it, the poll found.
The survey has a margin of error of 3 percentage points.