Though polling does not reflect an outpouring of love for private insurance, it is the devil Americans know. “There’s fear of change and comfort with what’s known, a bias toward the status quo, and it’s hard to quantify that,” says Topher Spiro, the Center for American Progress’s vice president for health policy. “There’s a real psychological issue that’s appropriate for policymakers to consider. I don’t think the people like us who are putting forth multipayer universal systems are doing so because we think insurers have some sort of superior efficiency or can improve the quality of care. It’s really a concern about how we get there the quickest in terms of political viability and with a minimum of disruption.”

Single-payer advocates play down the difficulty of transitioning into a government-run health care system. As Sanders puts it: “You have Medicare, a popular system that millions of people are already in. It seems to me the easiest way forward to get to universal care is to expand what’s already a popular system. I find it really amazing that people think this isn’t doable when back in 1965 they did Medicare without the technology we have today, and they were able to sign up 19 million people. So of course we can do it.”

But while the Republican efforts to gut Obamacare have bolstered support for a more ambitious health care policy, they have also clearly illustrated one potential downside of such a policy. “Medicare cuts are in Trump’s budget,” Tanden says. “If you’re worried about a Trump administration now, just imagine if the government has control of everyone’s health care. And I say that as a big-government liberal.”

The day before Sanders took to the debate stage in Detroit to defend Medicare for All, I met with him in a conference room at the Doubletree Suites hotel where he was staying. He was seated alone, wearing his customary off-the-rack navy suit and tieless white shirt, flanked by a Starbucks breakfast of coffee, granola and yogurt.

“We’ve got a health care crisis in this country,” he told me as he struggled with the plastic granola container, finally gouging it open with his car keys. Sanders has a reputation for being as beatific as a snapping turtle, but today he was happy(ish) to be discussing the topic that he and DeMoro had succeeded in crowbarring into the national debate. “You’ve heard me talk about F.D.R. in 1944 talking about economic rights as a human right,” he said. “That’s what we’re doing here, and I think with some success: changing consciousness in this country. Now everybody agrees health care is a human right. How you get there is subject to discussion. But that’s where we are.”

Recently Sanders had been campaigning in Las Vegas. While driving through the city, he marveled at the billboards advertising marijuana for sale. “Five years ago, corporations marketing marijuana would have been out of the question,” he said to the aides in his car. “Now they’re not only doing it, but it’s not even remarkable that they’re doing it. Politics change very quickly.”

A not-so-minor refinement to that thought would be: Politics change quickly as long as nothing is standing in the way. Nearly three decades have passed since Sanders and DeMoro began doing battle with the health industry and the political system. “What they do have is, they lie and they have an enormous amount of money — I get that,” Sanders conceded. “But I do think we’re at a moment in history where the American people are sick and tired of the insurance companies and drug companies. And I do believe we can beat them.”

For any movement, the answer to the question of how is not really legislative. The Rev. Martin Luther King Jr. had his dream. RoseAnn DeMoro told me hers recently. “I think it’s time now,” she said, smirking a bit as she studied her glass of white wine. “I think America needs to say to these C.E.O.s: ‘You’ve had your day. You’ve bought your 50 frigging yachts. But it’s over. Now let’s have health care in this country.’ ”/•/