Americans are not too enamored with the House GOP bill to repeal Obamacare.

Only 8% think the Senate should pass the legislation as is, according to a new poll from the Kaiser Family Foundation.

About half of respondents think the upper chamber should make either "major" or "minor" changes to it, while 29% say the Senate should not pass the bill.

One main reason: Nearly half of consumers say that their cost of health care will be "worse" under the House GOP's American Health Care Act, according to the poll.

That's compared to 16% who think the cost will be "better" and 36% who feel it will be "about the same."

Theresa Treece is among those worried that she'd have to shell out more for health care under the GOP bill. Treece, who had rheumatoid arthritis, credits Obamacare with making health insurance affordable for her.

The Paragould, Arkansas, resident had been uninsured for five years prior to Obamacare because she couldn't afford the $3,000 in monthly premiums for an individual market policy. Under the health reform law, she pays $300 a month.

Treece, 64, who recently retired as the office manager of a small home improvement business that didn't offer coverage, ticked off the problems with the GOP bill. It would allow insurers to charge older policyholders significantly more than younger ones. It would allow them to base premiums on a consumer's health status in some cases. It wouldn't cover annual checkups or preventative tests.

"The GOP has not come up with something better or cheaper. I don't care what they say," said Treece, who voted for Trump. "I'm worried about the cost. I'm worried about the coverage. The Republicans are not facing reality."

Related: Just 8% of Americans think the Senate should pass the healthcare bill as is. Wow

Other Americans agree. Just over one-third of respondents to the Kaiser poll felt the bill would worsen the quality of their health care and their ability to get and keep health insurance, the Kaiser survey found. Only 15% thought quality would improve, and 16% felt their ability to get and keep a policy would be better. (About half felt the bill wouldn't make much difference to them.)

Kaiser surveyed 1,205 adults in mid-May. They included those who are covered through an employer, Obamacare, Medicare or Medicaid, and those who are uninsured.

Overall, Obamacare enjoys much more positive ratings than the American Health Care Act. Some 49% view Obamacare favorably, compared to 31% for the GOP bill. That's the highest rating for Obamacare since shortly after it became law in March 2010.

Meanwhile, 55% of respondents had an unfavorable view of the GOP bill, compared to 42% who felt that way about Obamacare.

Related: Don't send me back to a high-risk pool, Obamacare enrollees say

Among the more popular provisions in the American Health Care Act are requiring non-disabled adults on Medicaid to work and providing federal funding to cover those with pre-existing conditions in separate high-risk pools, Kaiser found.

The least popular: Allowing health insurers to cut benefits so they can sell cheaper plans, letting insurers levy surcharges or base premiums on health status for those who let their policies lapse and raising premiums for older consumers, while decreasing them for younger ones.

Trump has said many times that he would repeal Obamacare and replace it with something much better and more affordable. But most Americans don't think the House bill lives up to those promises.

Senate Republicans are in the process of overhauling the House bill, but they are also struggling to bridge the many divides within the party.

Not helping matters: The non-partisan Congressional Budget Office last week released a report showing the House bill would leave 23 million more Americans without coverage by 2026 and send premiums soaring for many older Americans and for consumers with pre-existing conditions.

Related: GOP health care bill: Premiums may decline, but many will pay more for care

"The AHCA is starting at a much lower favorability rating so it's hard to see how the bill can be seen more favorably in the future," said Ashley Kirzinger, Kaiser's senior survey analyst.