The public is sending mixed messages about its views of the 2010 federal health care law--making the potential impact on the November election hard to judge.

By a 55-36 percent margin, people think the law has a tax increase, according to a new Quinnipiac University poll released Thursday. Most people have to obtain coverage by 2014 or face a penalty--or a tax, depending on one's point of view.

At the same time, voters said, by a 48-45 percent margin, they agreed with the June 28 Supreme Court ruling upholding the law.

Yet by 49-43 percent, they want it repealed. The House of Representatives Wednesday voted for repeal on a largely party line vote. The Democratic-run Senate is not expected to go along.

55 percent said a presidential candidate's views on health care matter. 59 percent said the court's decision will not affect their vote. But 27 percent said it would make them less likely to vote for President Barack Obama, while 12 percent said an Obama vote was more likely.

Obama is a strong supporter of the law; Republican presidential candidate Mitt Romney wants it repealed.

More mixed messages: People split 48-47 percent on whether coverage should be compulsory.

"The big question," said assistant poll director Peter Brown, "is whether the Republicans can sell the idea to voters that the president's Affordable Care Act breaks his promise not to raise taxes on those who make less than $250,000. That's why what voters believe on this issue matters."