Voters have a clearer idea of how to fix the U.S. health care system than many of the Democrats running for president.

The leading presidential contenders continue to debate Medicare for All, a sweeping new government program that would replace private insurance and require trillions of dollars in new federal spending. Senators Elizabeth Warren and Bernie Sanders are the biggest backers. Former Vice President Joe Biden favors more modest changes that would keep private insurance in place but offer more government help for people who can’t afford a private plan.

Voters seem to be siding with Biden. New polling by the Kaiser Family Foundation shows 51% of people favor Medicare for All, down from 59% last year. Other polling shows support for Medicare for All plummets when people realize it would mean abolishing private insurance and raising taxes.

The Kaiser survey, meanwhile, shows 73% of people favor a more limited public option that would keep private insurance in place. That’s up from 65% earlier this year. Among Democrats, 71% support Medicare for All while 85% support a more limited public program.

‘Free’ Medicare for everybody

Under Medicare for All, the entire U.S. population would be covered by a single government plan similar to Medicare, which primarily provides health care to Americans 65 and older.

Employers would no longer provide insurance, although it’s possible people would be able to buy supplemental coverage on their own from a private plan. All medical care would be “free,” with no premiums or out-of-pocket expenses. But that would require sharp tax hikes on most Americans. In addition to Warren and Sanders, other presidential candidates including Cory Booker, Kamala Harris and Andrew Yang support some form of Medicare for All.

Biden’s plan would leave private insurance intact, but give all Americans the option of enrolling in a government plan similar to Medicare. People would have to pay premiums to join the public plan, but those could be lower than private-sector premiums because government plans pay caregivers considerably less than private plans. Biden would also expand the Affordable Care Act by subsidizing coverage for more people. Other candidates including Pete Buttigieg, Beto O’Rourke, and Amy Klobuchar favor a new public option that leaves private insurance intact.

The difference between Medicare for All and a Biden-style plan

New analysis by the Urban Institute and the Commonwealth Fund highlights the considerable differences in costs and other tradeoffs between Medicare for All and Biden-style public option plans. Medicare for All would extend coverage to an additional 32 million people — including undocumented immigrants — essentially covering everybody in the country. But it would require $2.8 trillion per year in new government funding, which can only come from higher taxes. And it’s unknown how doctors and other caregivers would react to sharp cuts in payments, though some would probably leave the profession, creating longer wait times for some care.