Medicare for All Would Abolish Private Insurance. ‘There’s No Precedent in American History’

Many supporters of this approach see elimination of private insurance as a key feature, not a bug, meant to improve the program’s efficiency and equity by streamlining the health care system and weakening profit motives. With a single insurer covering every patient, hospitals and doctors could spend less time and money complying with differing policies, negotiating contracts, and filing forms to get paid.

“It’s worth it,” said Adam Gaffney, the president of Physicians for a National Health Program, which supports single-payer health care and helped design Ms. Jayapal’s bill. “Because we are not going to get to true universal health care without the greater efficiency of a single-payer system.”

This idea — once at the edge of Democratic politics — has moved to the mainstream of the debate among the party’s numerous presidential contenders. Mr. Sanders, independent of Vermont, ran on the idea in his 2016 campaign, and now five 2020 Democratic aspirants have co-sponsored one of the two Medicare-for-all bills.

Senators Cory Booker of New Jersey, Kirsten Gillibrand of New York, Kamala Harris of California, and Elizabeth Warren of Massachusetts co-sponsored Mr. Sanders’s bill in the last Congress. Representative Tulsi Gabbard of Hawaii is a co-sponsor on this year’s House Medicare for All Act.

The concept, in broad strokes, appeals to many Democratic voters. But overall support diminishes by a third or more when people are told that the plan would involve eliminating private insurance, raising taxes, or requiring waits to obtain medical care, according to surveys from the Kaiser Family Foundation.

And the approach is a big departure from the Democrats’ strategy in 2010, when Congress passed the Affordable Care Act. That law expanded coverage, but did so largely using private insurance carriers. It set up marketplaces for Americans who didn’t have coverage through work to buy insurance, usually with federal subsidies, and broadened access to the Medicaid program for the poor.

Obamacare was designed to build on the current system, patching its holes while minimizing disruption and avoiding the fierce opposition from industry that helped sink earlier attempts to change the health care system.