Since the fourth Democratic debate in October, the first time Sen. Elizabeth Warren (Mass.) was treated as a kind of co-frontrunner and assailed pointedly by other candidates, her seemingly unstoppable momentum in the Democratic primary has stalled out. With former Vice President Joe Biden recovering a bit in the polls, fellow progressive Bernie Sanders given new life by endorsements from prominent figures like Alexandria Ocasio-Cortez, and even South Bend, Indiana, Mayor Pete Buttigieg surging in Iowa, the race once again has a wide open feel.

While Warren is still in a very strong position, particularly in the first states to vote, her nomination no longer feels almost inevitable. What happened?

First, as the New York Times/Siena polls demonstrated earlier this week, like all women in the race, Warren suffers from pervasive sexism. And there is real, if overblown, concern in a sector of the primary electorate about her "electability." But there seems to be something else going on, and it's not the need for Warren to abandon her Medicare-for-all plan in order to win over swing voters, a gambit just as likely to alienate core supporters as it is to convince moderates. It has nothing to do with the relentless discourse about how it will never get passed into law anyway.

In that fourth debate, Warren was pressed repeatedly on the cost of her Medicare-for-all proposal. When pushed by moderators to say whether it would require a middle class tax increase, Warren evaded the question repeatedly by saying "costs will go up for the wealthy and for big corporations, and for hard-working middle-class families, costs will go down."

An artful dodge, perhaps, but a dodge nevertheless. Most people understood that she was trying very hard not to say the word "taxes." The logic of this strategy had its merits — don't say anything that can be weaponized so easily by GOP attack ad makers in the fall — but might have left voters feeling like their intelligence had been insulted. And the cumulative effect of the pushback from moderates like Sen. Amy Klobuchar (Minn.), Biden, and Buttigieg felt significant.

Recognizing post-debate that she was going to have to answer this question one way or the other, and attempting to distinguish her plan from that of Bernie Sanders, who has admitted forthrightly that taxes must go up, Warren spent weeks putting together a comprehensive proposal both to satisfy her deficit-scold critics and to put an appealing wedge between herself and Sanders. On the bright side, this plan, released on Nov. 1, allows her to claim with some coherent internal logic that she will not raise taxes on anyone but the rich. On the downside, it plunged her into another set of internecine debates, both with critics from the left who dislike some of its financing mechanisms, and centrist austerity hawks who will never accept any of her plan's fiscal logic anyway.

I'm not here to weigh in on the merits of the proposal itself, but to suggest that rather than arguing about the plan's financial logic — which is unlikely to be rewarded in a meaningful way either by the press, debate moderators, or her opponents — Warren's campaign might be better off soothing fears about disruption rather than cost.

To understand why disruption is the more pertinent concern, think about the last time your employer switched your insurance on you. Were you worried about how your employer was paying for the new plan or whether your premium was going up or down by a few dollars a month? Or was your first question about whether your doctor would be in whatever new network was being foisted on you and whether your prescription drug costs would go up or down?

The hunch here is the latter. Democratic primary voters at least might be inclined to assume that the total costs to their household under the Warren and Sanders plans might really be a wash. Where they may be getting uncomfortable, particularly as the prospect of a candidate committed to this idea actually getting elected president becomes more and more plausible, is thinking about how it is all actually going to work.

The overhaul of the health-care system that the progressive candidates are proposing would be the most enormous and consequential public policy undertaking that anyone under the age of 80 has ever lived through. Unlike Medicare, Medicaid, or even Social Security, it will immediately affect everyone with a pulse in the United States. It is fair to ask that anyone proposing to do this be capable of answering good-faith questions in plain terms that everyone can understand.

A short list of these kinds of gnawing questions would include things like: How does the government plan to scale up the administrative apparatus of Medicare? How many people need to be hired and where and at what cost? What is the plan to produce even more health-care providers in a system that is already experiencing a massive doctor shortage? What will happen to health-care systems and hospitals that depend on the existing cost structure of American health-care — largely the ability of providers to make up absurd costs and pass them on to insurance companies and ultimately to us?

Will the whole system of medical training and pay need to be nationalized as well, as it is in the U.K.? The American model depends on asking doctors to go $200,000 in debt for training and then to work the most insane hours of any professionals on the planet in exchange for being dramatically better paid than their developed-world peers. Obviously, to bend the cost curve down, that's going to have to change, and it's worth asking exactly how. The point of pondering these questions isn't that there are no answers — many societies including the U.K. and Canada capably operate systems similar to the one that Warren would like to bring into existence, at lower overall societal costs and with better results. This is not even in dispute by serious analysts. The point is to reassure people that this is doable, that she has thought about it and that she has a plan for it.

A real conversation about implementation, importantly, would allow Warren to convince voters that she doesn't plan to blow up their health-care world — however predatory, overpriced, and infuriating it may be — overnight. Few seem to have noticed this, but in her plan, Warren repeatedly refers to "my long-term goal of Medicare-for-all." She talks about a 10-year plan. And the closing section of her proposal, which has gotten zero attention, promises another forthcoming plan to address the concerns of all stakeholders in the current system "who worry about what a new system will mean for them."

In other words, Warren's Medicare-for-all plan is obviously something that will be phased in over the course of many years. Voters don't need to be told how much it will cost — as soon as the dollar figures and years start flying around during debates, people's eyes go glassy and they reach for the remote.

What people really need to be told is that everything will be okay. And the sooner Warren can turn the conversation away from cost and toward a vision of what this new health-care system will look and feel like, the better.

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