Single-payer health care is not a new idea, not even here in the United States, the only wealthy Western nation without universal coverage. In 1944, President Franklin Roosevelt proposed a Second Bill of Rights that included “the right to adequate medical care and the opportunity to achieve and

enjoy good health.” Roosevelt, of course, spoke at a heady moment, when Democrats were signing up as co-sponsors for sweeping national health-care legislation. After Roosevelt’s death, Harry Truman embraced the cause and agitated for it more aggressively than any president since, only to be blocked by a Red Scare that presaged McCarthyism, as well as a vicious campaign funded by the American Medical Association.

President Lyndon Johnson used his 1964 landslide election to enact Medicare and Medicaid, but the Democratic presidents who came after him have pulled their punches on health care—mostly promoting schemes to better organize the intersection of private and public care that mirrored those once advanced by a dying breed of moderate Republicans.

And here Democrats have paid a political price, not for compromising on any eventual legislation, but for failing from the outset to put forward a clear and simple vision of health care as a fundamental right. In 1993, Bill and Hillary Clinton produced a byzantine and dispiriting plan that blended new regulations, subsidies, mandates, and free-market competition in a stew they called “managed care.” “We have no pride of authorship” over any aspect of the bill, they both conceded during the rollout. Lacking a moral center, the proposal died quickly under a withering attack from the right and the insurance industry. Barack Obama, of course, was considerably more successful in this regard. But he began the negotiations by preemptively taking single-payer off the table, despite having repeatedly stated that such systems make the most sense. With Obama’s punt, there went any room to negotiate even for a public option.

Now Democrats find themselves yet again defending a law that even its eponymous sponsor publicly acknowledges needs significant fixes. Make no mistake, the latest Republican attempt to repeal and replace Obamacare—this time with the Graham-Cassidy bill—is in many ways stupider and crueler than its predecessors. There is no Congressional Budget Office score yet for this hasty, last-ditch effort, but replacing most of the Affordable Care Act with inadequate block grants to states, along with other cuts, will easily leave upwards of 32 million people uninsured. Seemingly as a middle finger, the bill disproportionately targets the blue states that expanded their Medicaid rolls. To this moral obscenity, Democrats have been unified in saying no. But what are they saying yes to?

Enter Senator Bernie Sanders. Building from a presidential campaign that rocked the Democratic Party establishment by putting unabashedly progressive proposals front and center, Sanders has used his newfound stature to assemble an unlikely coalition of Democrats to back a “Medicare for All” bill.

The basic premise isn’t novel: Medicare for All has been introduced in the House of Representatives by Congressman John Conyers for over a decade, as well as promoted by groups like Physicians for a National Health Care Program and the National Nurses United. Four years ago, when Sanders proposed a similar measure, he found exactly zero co-sponsors. Today he has 16, including prospective 2020 presidential candidates Elizabeth Warren, Kamala Harris, and Cory Booker. So what changed?

Galvanized by the economic and social movements that found expression in Sanders’s campaign, Democrats are undeniably more willing to embrace big ideas, even and especially in the age of Trump. As Hillary Clinton observes in her memoir What Happened, “the conclusion I reach from this is that Democrats should redouble our efforts to develop bold, creative ideas that offer broad-based benefits for the whole country.” On health care in particular, according to a recent Pew survey, a majority of Americans now believe that the federal government should be responsible for making sure everyone has coverage, and a majority of Democrats think that single-payer is the best way to achieve that goal. All of this forms the context for the sudden popularity of Medicare for All, but there is also a quieter genius to Sanders’s particular bill that helped bring about this moment.

The Medicare for All Act of 2017 is unambiguous about its goal: It would eliminate all private insurance and replace it with a vastly expanded government program. Doctors, hospitals, and drug companies would make less, but everyone would have access to comprehensive health services—including dental, vision, substance-abuse treament, and reproductive care—without any out-of-pocket costs. That is its principle, and it is unwavering about it.

The bill’s pragmatism lies in how it gets there. Medicare expansion would spool out over several years, first by enrolling children under 18 and dropping the eligibility age to 55, a step that even non-backers like Senator Tim Kaine support. By its fourth year, incremental expansions would finally create a true Medicare for All program. During that transition, many people who are uncovered would be able to buy into the system through provisions championed by Senator Kirsten Gillibrand, who supports the bill, and Senator Debbie Stabenow, who doesn’t—yet.

Canvassing his fellow senators, including those who have taken a wait-and-see approach, was key to Sanders’s ability to build a surprisingly broad base of support, as was the backing of dozens of outside groups, from to the Working Families Party to the United Mine Workers. That Sanders was one of the most vocal defenders of Obamacare—even as he consistently criticized it as insufficient—helped build credibility, too.

Of course, Medicare for All is still a long way from becoming reality. Republican control of Congress and the White House is the most obvious impediment, and that’s before we see the insurance industry, the hospital industry, and Big Pharma devoting every ounce of their awesome power and influence to destroy it. And yes, there are still holdouts in the Democratic Party who carp about the costs, or insist that we have to focus on protecting Obamacare first before going for single-payer—as if you can’t do both at the same time.

But thanks to a deft mix of politics and policy from Senator Sanders, that faction shrank dramatically in the past year. And that, in addition to its promise to not only improve the health but save the lives of millions of Americans, may be one of Medicare for All’s most enduring legacies—the beginning of the end of the Democratic Party’s unthinking and self-sabotaging belief in the idea that principle and pragmatism can’t coexist.