If you want to know why Democratic senators with national ambitions are suddenly falling over each other to endorse a Medicare-for-all bill, of course Bernie Sanders has something to do with it. So do the activists who’ve been fighting for this for years, and so does the National Nurses Union.

But single-payer activists have been out there for a long time. So has Sanders. And Sanders didn’t win the 2016 primary, and it’s not like his national political organization, Our Revolution, has been knocking off Clinton-endorsing incumbents.

The critical difference is Donald Trump and, to an extent, the broader Republican Party. Their relentless efforts to undermine the Affordable Care Act are undermining the “pragmatic” rationale Democratic leaders offered in 2009 for pursuing universal coverage through a system reliant on private insurance.

The hope was that by aligning with key industry priorities, they could not only minimize short-term disruption but earn Republican Party buy-in and stabilize the system. It hasn’t worked. And the extent to which Trump is doing everything in his power to undermine the ACA’s marketplaces underscores that it won’t.

It’s still difficult to see exactly how we get from Sanders’s squad of high-profile co-sponsors to workable legislation that can command congressional majorities. Sanders, speaking to Vox’s Jeff Stein, called on the United States to “join the rest of the industrialized world” in recognizing health care as a right, but in practice his bill promises a more generous (and thus expensive) benefits package than any foreign country.

But it’s easy to see that Republicans aren’t interested in letting Barack Obama’s signature legislation serve as a stable answer to the question of how American health care is supposed to work. Even with legislative repeal evidently failed, the Trump administration is using its powers to sabotage the functioning of ACA marketplaces, crippling outreach and sign-up efforts while doing nothing to encourage insurers to participate.

So unless Republicans have a sudden change of heart and get Trump to try to make the ACA marketplaces work, Democrats are going to have to keep fighting back. And if Republican administrations are going to actively undermine public-private marketplaces, they have nowhere to go but left — pushing for a larger role for government-provided insurance that can’t be undermined as easily.

The Obamacare compromise never stuck

One key theory behind Obama’s health care legislation was that as long as he was talking about raising taxes to spend a bunch of money on giving more people health care, he might as well try to turn the health care industry into his allies.

This quickly ran into trouble when it turned out that even a bill endorsed by pharma and the major relevant trade associations (doctors, hospitals, insurance companies) couldn’t actually secure any Republican votes.

Between grassroots hostility to Obama, non-transactional billionaire outside donors like the Koch brothers, a strategic calculus from Mitch McConnell that maximum obstruction would deliver electoral benefits, and the perennial hothouse atmosphere of Fox News and talk radio, interest group buy-in turned out not to matter that much.

What’s even more striking is how little interest group buy-in seemed to matter after the 2016 election when Republicans set about trying to repeal and replace the Affordable Care Act. Paul Ryan’s American Health Care Act sailed through the House of Representatives without so much as a Congressional Budget Office score or a committee hearing despite dismal public polling and opposition from every relevant health industry group. In the Senate, the insurance industry proved relatively easy for McConnell to buy off, and even though other industry groups formally opposed the bill, they didn’t go to war over it because they fundamentally like the idea of tax cutting, deregulating, business-friendly Republicans in power.

The effort came up just one vote short of what was needed to enact a sweeping rollback of Obamacare.

Trump is still sabotaging the law

What’s even more remarkable is that having failed to repeal the Affordable Care Act, the Trump administration is still trying to sabotage its implementation.

Some of this stems from continued monkeying around with cost-sharing reduction payments that insurance companies are counting on to keep their state risk pools stable. This is contributing to the continued pop-ups of counties with no Obamacare insurance plans on offer, and the Trump administration seems perfectly happy with that outcome. Trump is also massively cutting funding for Affordable Care Act outreach in a way that experts — including the woman who used to run the outreach programs — say could ruin the functioning of the law.

This is a fairly extraordinary set of affairs. Presidents (and governors, mayors, and other executive officials) normally try to make things work better rather than worse so they can claim to have solved problems and take credit for improvements in people’s lives.

Donald Trump is, obviously, an unorthodox politician in many ways, and he has succeeded in the face of massive skepticism before, so he is trying something different — deliberately making things go worse for people and hoping that proves he was right all along about Obama. Trump’s determination to pursue that course means that if Democrats find themselves back in the White House in 2021 or 2025, they won’t be able to just take up where Obama left off. They’ll have to deal with the health care issue — whether they want to or not.

Health care is going to be on the agenda

Back in the 2016 campaign, one major source of resistance to single-payer proposals from Democratic Party elites was a sense that the policy agenda had to move on to other topics.

In the 2009-’10 cycle, important issues like climate change and immigration reform had taken a back seat to health care and ended up being addressed through tenuous executive actions rather than legislation. New ideas like universal preschool and paid family leave, meanwhile, had bubbled up to the top of the social policy stack.

In theory, of course, there’s no reason a country couldn’t have a single-payer health care system and a universal preschool system and a paid family leave system (Finland does), but in a practical political sense, you need to tackle issues in order. The party consensus was to leave the ACA in place, keep working on Medicaid expansion at the state level to drive the uninsurance rate lower, and try to build working legislative majorities to tackle other subjects.

And had Hillary Clinton become president, that would have worked. Indeed, had Bernie Sanders become president, he still would have faced considerable pressure to set single-payer aside and work on paid leave and preschool, just as Obama set climate change aside in 2009 to work on health care.

But Trump’s sabotage ensures that health care will stay on the agenda. And as long as it’s on the agenda, progressives are going to push for what they’ve wanted all along: a unitary government-run system. And the fact that under Trump, the government-run portions of the health care system are running better than the public-private hybrid part is only encouraging them.

The marketplaces are public health care’s weak link

Even as Trump tries to sabotage the Affordable Care Act’s marketplaces, he finds himself fundamentally unable to rid himself of the law’s major Medicaid expansion. And as Senate Republicans pondered repeal of the law, they ultimately ended up finding that there was more legislative support for a “skinny” repeal bill that would wreck the marketplaces and leave Medicaid intact.

Trump himself, meanwhile, has promised not to cut Medicare and seems to be sticking to that promise. Ryan, who rose to prominence as the ranking member of the House Budget Committee by proposing Medicare cuts, has now dropped his own Medicare privatization schemes from the House’s effort to write a budget resolution.

The bits of the system directly run by the government, in other words, have proven more robust to political attack than the complex public-private hybrids whose creation was inspired by political pragmatism.

Democrats are all rowing in the same direction

Despite its flashy rollout, the actual prospects for Sanders’s legislation are dismal and would remain dismal even if Democrats ran a couple of big electoral victories.

Not only is the amount of tax increases that his program would require astronomical — his “Medicare-for-all” benefits package is much more generous than actual Medicare, for starters — but things like taxpayer-funded abortions and government health care for undocumented immigrants are very unlikely to survive any kind of real-world legislative process.

The real sign of where things are going is that essentially all the big Democratic ideas on health policy head at least broadly in this direction. Whether it’s Brian Schatz’s idea of turning Medicaid into a nationwide public option or Sherrod Brown’s Medicare buy-in for people over 55 or Chris Murphy’s broader Medicare buy-in scheme, the action is all in the expansion of government programs.

Hillary Clinton, telling Ezra Klein why she thinks Sanders’s program is a mistake, says Democrats should instead say, “You know what, we need to lower the age for Medicare, and here’s how we can do that, and we need to continue the expansion of Medicaid.”

Nobody is talking, as even Obama was a few years ago, about raising the Medicare eligibility age or turning the regulated marketplaces into an alternative to the employer-based system.

Thanks to Trump, Democrats have no alternative but to once again try to address the question of health care. And thanks to Trump and the broader Republican Party, they have essentially nowhere to go but left as they try to do it.