There isn’t much doubt who has the momentum (for whatever that’s worth) in the Democratic presidential primary. Sen. Elizabeth Warren (D-Mass.) is drawing huge crowds. While former vice president Joe Biden and Sen. Bernie Sanders (I-Vt.) are dropping in many polls, she’s rising; a new Monmouth University poll shows the three virtually tied for the top spot nationally.

Meanwhile, Warren seems to be wowing voters and party insiders alike. And a big part of her appeal is the image she has cultivated as the candidate who has thought the most about the challenges of governing, with a plan for everything.

So where’s her health-care plan?

It’s an almost bizarre omission that barely anyone has seemed to notice, given that it’s the domestic issue that gets more discussion than any other. It’s not that Warren doesn’t talk about health care, or that she hasn’t been clear about what she believes in a general sense, because she does and she has.

But, so far, she has avoided some of the trickiest questions by not putting specifics down on paper. Warren co-sponsored Sanders’ Medicare-for-all bill in the Senate, but she has also co-sponsored other bills offering substantial but less-sweeping reforms. And whenever she talks about the issue, she discusses different priorities for different time periods: Right now, stop the Republican assault on the Affordable Care Act; then, start expanding coverage and strictly regulating insurance companies; ultimately, move to Medicare-for-all to cover everyone.

We should say that a lot of requests to clarify health-care details are often little more than bad-faith attempts to get the Democratic candidates to say something they’ll be attacked for (“Are you gonna raise taxes? Are you? Are you?”). But the details are important, even if some of them may change as any proposal is wrung through the legislative grinder.

When you’re forced to get specific, people will inevitably find things to criticize. If Warren releases something like Sanders’ plan, it’ll be called unrealistic; if she takes a more step-by-step approach to reform, some on the left will call it a betrayal.

We saw this with Sen. Kamala D. Harris (D-Calif.),/ Harris, who had made statements similar to Warren’s about supporting Medicare-for-all and getting rid of insurance companies which provide no real added value, extract profits, and make people’s lives miserable and full of uncertainty and fear. But when Harris released her plan, it was criticized as an attempt to not turn her back on what she had promised while accommodating the criticisms Medicare-for-all had received — particularly the worries about people losing private coverage.

For the record, I thought much of that criticism was unfair, particularly the idea that the 10-year transition to (nearly) full single-payer in Harris’s plan was too slow. That kind of ambitious reform will be incredibly disruptive even if it brings us to a better system, and 10 years is not too long to make sure it’s happening in the right way.

Nevertheless, no plan from a candidate can be immune to political considerations, and one thing all the candidates are surely considering is that recent polls seem to show a shift away from Medicare-for-all of the kind Sanders proposes — a true single-payer system in which private insurers have little or no role almost from the outset — and toward something more like Medicare-for-anyone, a voluntary system which would beef up public insurance and cover all the uninsured but wouldn’t be mandatory.

In some formulations, that’s an end point, while in others it’s a means to achieve Medicare-for-all over time, as people steadily realize the public plan is better and abandon private insurance for it; this is how Sen. Kirsten Gillibrand (D-N.Y.), for instance, describes her vision. Either way, it seems to be hitting some kind of public opinion sweet spot; recent polls have shown substantially more support even among Democrats for a system based on a public option than one that eliminates private insurance quickly.

I would be shocked if Warren and her policy team aren’t well aware of the shape of public opinion, even as they’re trying to come up with the most effective plan they can. That might account for why she has released plans on so many other issues but not on this one. (I’ve asked the Warren campaign when she will release a plan and will update if they answer.)

The longer she waits, the more time she has to see how things shake out and come up with something that will solve the system’s problems without engendering too much of a campaign backlash. But she won’t be able to wait for much longer.

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