Asked if they believe the Affordable Care Act "is in effect a tax hike," 55 percent of voters responded that it is while 36 percent said it is not, the Quinnipiac University poll found.
The poll also found 48 percent of respondents agreed with the U.S. Supreme Court decision upholding key provisions of the law, while 45 percent said they disagreed with the decision. However, 49 percent said Congress should repeal the law, while 43 percent said it should not be repealed.
More than half, 55 percent, said a presidential candidate's position on healthcare is "extremely important" or "very important" to their vote.
Fifty-nine percent said the Supreme Court ruling will not affect their votes, while 27 percent said the decision would make them less likely to vote for President Obama and 12 percent said it would make them more likely to do so.
The poll showed voters nearly evenly split on whether Americans should be required to have health insurance, with 48 percent saying they support the requirement to 47 percent who said they oppose it.
The poll found 76 percent of Republicans said they opposed the individual mandate while 19 percent of Republicans said they supported it. Democrats said they supported the mandate by a margin of 79 percent to 16 percent.
On immigration, 55 percent said they approve of Obama's new policy ending deportation of some young illegal immigrants to 39 percent who said they oppose the policy. By a margin of 61 percent to 34 percent, voters said they want an Arizona-like immigration law in their state, requiring police to check the immigration status of someone they stop or arrest or if police suspect a person is in the country illegally.
Results are based on telephone interviews July 1-8 with 2,722 registered voters. The poll has a margin of error of 1.9 percentage points.