Beto and Bernie are pulling Democrats in different directions on health care policy. Photos: Chip Somodevilla/Getty Images

There’s an ancient debate within the Democratic Party about how (and how quickly) to move the country toward universal health coverage. The enactment of the Affordable Care Act was the high point of one basic approach: incremental, involving both public and private insurance, and minimally interfering with existing arrangements. The many dissatisfactions, substantive and political, with Obamacare have fed a revival of the other basic approach: a full leap into a single-payer system operated by the federal government.

The preeminent single-payer scheme of the moment is Bernie Sanders’s proposal, which he has wisely dubbed Medicare for All, trading on the popularity of the Great Society–era health insurance program for seniors. The title is a bit of a misnomer, in that it would change Medicare itself in very significant ways. But once you get past that issue, it’s pretty straightforward: private insurance would be abolished, as would copays, deductibles, and premiums; Medicaid and Obamacare would be folded in; and the cost of this massive new Medicare program would be fully socialized through taxes. The basic appeal of the proposal is its simplicity and equality, and the proposition that most people would pay less in higher taxes than they’d save in premiums and out-of-pocket expenses.

The two obvious problems with Medicare for All are those higher taxes (Sanders proposes a combination of new employee and individual taxes and making existing federal income taxes more progressive), and the disruption of existing insurance. That would include not only the employer-sponsored insurance that covers roughly half the U.S. population, but the Medicare Advantage plans offered by private insurance companies that cover a third of the Medicare population.

These are pretty big problems, so unsurprisingly, the world of left-of-center think tanks has generated a different initiative building off Medicare, called Medicare for America. That this initiative isn’t some sort of timid Clintonian, incremental improvement of existing law is signaled by the names of its two chief congressional sponsors, Rosa deLauro and Jan Schakowsky, both stalwarts of the Congressional Progressive Caucus. It is probably best understood as a “public option” on steroids: it would enroll Medicaid and Obamacare participants in Medicare, while making it a voluntary option for everyone else, regardless of age. Out-of-pocket expenses would be capped, not abolished, and premiums would be maintained on a means-tested sliding scale.

Because the federal government would continue to obtain revenues from premiums, and enrollment would presumably be less than universal, Medicare for America would be less of a fiscal leap than Medicare for All. And no one would be forced to give up her employer-sponsored insurance or Medicaid Advantage plan. The grand idea is a gradual transition to the kind of single-payer system Sanders’s proposal would initiate immediately.

These two proposals aren’t just competing in the abstract world of health care wonks. Sanders’s plan is at the center of his own presidential campaign, and has been embraced to one degree or another by Cory Booker, Kamala Harris, and Elizabeth Warren, among others. Medicaid for America has won an important new advocate in Beto O’Rourke. And because so many Democratic politicians (not to mention voters) are more than willing to support alternative plans that vary in cost, scope, and ambition, it won’t be surprising if O’Rourke is joined by others, regardless of their position on Medicare for All.

Even though either proposal would represent a significant leftward move for the Democratic Party and the country, and would also cast a large shadow over more modest “centrist” proposals like a limited Medicare buy-in opportunity, the emergence of Medicaid for America could collide with the determination of some progressives to make Medicare for All a non-negotiable demand (or as detractors put it, a “litmus test”). As Dylan Scott observes, it’s unclear how deeply that idea is rooted in the opinion of rank-and-file Democrats:

I have wondered for some time how many absolutist single-payer acolytes there really are within the Democratic Party. A January poll by the Kaiser Family Foundation found that 81 percent of Democrats support a single-payer Medicare-for-all plan — but support for a plan like Medicare for America, opening government coverage to everyone but allowing people to keep their current plan if they so choose, was a little higher, at 91 percent. Like the rest of the public, Democratic support for single-payer rose when they heard out-of-pocket costs would be eliminated and every American would be guaranteed coverage. But then support fell when they were told it would lead to higher taxes or delays in medical treatment.

Another poll, taken by Democratic pollster Michael Perry, found that just 11 percent of Democrats say they would support only Medicare-for-all, because incremental reforms prop up a broken system. The vast majority — 84 percent — said they support Medicare-for-all and more gradual improvements to the Affordable Care Act.

So long as the two big Medicare proposals are understood as two paths — one very simple and equitable, one perhaps more feasible and less disruptive — to the same goal, they may play a limited role in the 2020 Democratic primaries (Republicans will, of course, savage both as “socialized medicine” and as an effort to soak hard-working white taxpayers to provide still more benefits to coddled and idle minorities). But the Beto-versus-Bernie dynamic could make a lot of wonky health policy distinctions politically salient right away.