About one-fourth of Americans say Obamacare has hurt them, according to a poll released Monday, while 15 percent say the law has helped them.

Fifty-six percent of respondents to a poll sponsored by the Robert Wood Johnson Foundation, National Public Radio and Harvard University said the Affordable Care Act has had no direct impact on the people in their state. Twenty-five percent said it's directly hurt them while another 15 percent said it's directly helped them.

The healthcare law remains politically controversial six years after Congress passed it and President Obama signed it. Yet polls consistently find that a majority of Americans say they haven't been directly affected by the legislation, which expands federally subsidized health coverage to the poor and middle-income people but largely left the existing system of employer-sponsored coverage alone.

All of the Republican presidential candidates have vowed to repeal and replace the law should they ascend to the White House, and even Democratic front-runner Hillary Clinton has said she would like make some changes to it. Her Democratic rival, Sen. Bernie Sanders, is campaigning on a single-payer system instead of Obamacare.

Congress has voted more than 70 times to repeal parts or all of the law. Polls have consistently shown the public is evenly divided over whether they would like to see the law go or stay.