Not that it has much chance of passing in a Republican-controlled Congress, but the Center is bringing out the plan regardless. Neera Tanden, president of the Center, is quoted saying in the report, "We think it's time to go bolder," adding, "There is consensus on the progressive side that universal coverage should be the goal and health care is a right."

And while Republicans are already jumping on the bandwagon to disparage the plan, they might do well to remember that not only was the Center's 2005 proposal on health care a foreshadowing of the Affordable Care Act, but the Center itself has been aligned with former President Barack Obama and 2016 candidate Hillary Clinton. And while the current administration's popularity is low, Obama's profile has actually risen since he left office.

Under the proposal, the report says, Medicare Extra would use Medicare's money-saving payment system "as a framework to pool working-age people and their families, low-income people now covered by Medicaid and seniors."

At the moment, there's no cost estimate for the plan, although its authors say one is in progress. And a nonpartisan expert who reviewed the Medicare Extra plan independently has said it could give Democrats a middle way to bring about coverage for all.

"It's an attempt to capture the enthusiasm for a single-payer system among the Democratic base, but trying to create a more politically and fiscally realistic roadmap," Larry Levitt of the nonpartisan Kaiser Family Foundation is quoted saying in the report. He adds, "It is in some ways 'repeal and replace,' but from the left rather than the right."

Medicare Extra's main features include automatic eligibility for coverage for all U.S. citizens and lawful residents, as well as free preventive care, treatment for chronic disease and generic prescription drugs. Dental, vision and hearing services would be included.

Low-income people would have no premiums or copays, while income would decide premiums and copays for all others. Employers could participate or not, while employees could choose Medicare Extra or stick with their employer's plans; tax-free status of employer-provided health care would remain, subject to a limit.

Seniors with private Medicare Advantage insurance plans through Medicare could keep similar coverage through a redesign of the program called "Medicare Choice." They would also gain coverage for vision, dental and hearing services, as well as long-term care services. Medicare currently does not provide any of those.

Last but not least, the government would negotiate prices for prescription drugs, medical devices and medical equipment.

Taxes would be higher, of course, and the government would play a more prominent role in health care, but some of the options identified in the report as possible ways to pay for it include a rollback of some of the recently enacted GOP tax cuts for corporations and upper-income people, raising Medicare taxes on upper-income earners and tax increases on tobacco and sugary soft drinks.