The most critical argument Democrats will have in 2020

For these practical reasons, as well as political considerations, Starr thinks it’s highly likely that in the general election, any Democratic nominee will shift to a position of allowing private health insurance to coexist with an expanded public alternative (though even that, he cautions, may be more complicated than it now appears). Other Democratic policy and electoral analysts agree.

“I think that there is a majority sweet-spot position for a universal-health-care plan that relies heavily on public insurance, but doesn’t eliminate private insurance,” says Neera Tanden, the president of the liberal think tank the Center for American Progress and a former chief domestic-policy adviser for Hillary Clinton. “In this case, in an election where people are concerned about electability, I do think lots of voters are anxious about anything, policy or otherwise, that can detract from defeating Donald Trump.”

But there’s no guarantee Democrats end up in that place. And the argument that is likely to gather momentum into the next debates may determine not only whether they do, but also how many scars they acquire along the way. “The challenge for the Democratic Party … is to go through this process and ensure that health care remains a top-tier positive issue for [the general election],” Tanden says. As the party’s divide over a single-payer system widens, that may be easier said than done.