"Medicare for all"
How to turn a meaningless slogan into something worthwhile
Senators Bernie Sanders, Elizabeth Warren and Cory Booker are all for it, as are Kamala Harris and Kirsten Gillibrand.
"Medicare for all" has also become a rallying cry for many Democratic activists as the mid-terms approach.
Like "repeal and replace", the Republican Party's three-word proposal for improving on Obamacare, "Medicare for al" sounds good but is largely meaningless.
Ask any five Democratic senators what they have in mind and you will get five different answers.
The urge to reform American health care deserves support.
America is the only rich country to lack universal coverage.
Even in a booming economy, 12% of American adults remain uninsured.
Though the best care they receive is world-beating, the system as a whole has high costs and disappointing results.
America spends 17% of GDP on health care, the highest of any rich country,
but in return achieves an average life expectancy no better than that of the formerly communist countries of eastern Europe.
Even Americans with good insurance plans find dealing with their providers maddening.
Hence the urge to tear up the whole system and start again.
Mr Sanders has done the most to popularise Medicare for all.
He proposes converting the government scheme for the elderly into a single-payer system funded from general taxation, as in many European countries.
Private companies would still provide the care, unlike Britain's NHS, but individuals would no longer buy health insurance through their employers.
This plan appeals to Democrats scarred by their experience with Obamacare, an incremental reform that worked with the grain of America's market-based system but which Republicans successfully targeted as unjust.
To avoid repeating the same mistake, the thinking goes, Democrats need a big-bang reform that cannot be unpicked later.
Its backers point to polls showing overwhelming support for Medicare for all.