The details of the Senate GOP’s Obamacare replacement plan remain a mystery. But the argument Majority Leader Mitch McConnell is using to push the final product over the finish line isn’t.

On Friday, McConnell reportedly “delivered a private warning to his Senate Republicans: If they failed to pass legislation unwinding the Affordable Care Act, Democrats could regain power and establish a single-payer health-care system.”

History may record a certain irony if this is the argument McConnell uses to successfully destroy Obamacare. In recent conversations with Democrats and industry observers, I’ve become convinced that just the opposite is true: If Republicans unwind Obamacare and pass their bill, then Democrats are much likelier to establish a single-payer health care system — or at least the beginnings of one — when they regain power.

“I will tell you,” says Len Nichols, director of the Center for Health Policy Research and Ethics at George Mason University, “Democratic politicians I never thought would utter the words have mentioned single-payer to me in a non-joking way of late.”

If Republicans wipe out the Affordable Care Act and de-insure tens of millions of people, they will prove a few things to Democrats. First, including private insurers and conservative ideas in a health reform plan doesn’t offer a scintilla of political protection, much less Republican support. Second, sweeping health reform can be passed quickly, with only 51 votes in the Senate, and with no support from major industry actors. Third, it’s easier to defend popular government programs that people already understand and appreciate, like Medicaid and Medicare, than to defend complex public-private partnerships, like Obamacare’s exchanges.

The political fallout from passing the American Health Care Act — which even Donald Trump is reportedly calling “mean” — will also be immense. In passing a bill that polls at 20 percent even before taking insurance away from anyone, Republicans will give Democrats a driving issue in 2018 and beyond — and next time Democrats have power, they’ll have to deliver on their promises to voters. Much as repeal and replace powered the GOP since 2010 and dominated their agenda as soon as they won back the White House, if the American Health Care Act passes, “Medicare for all” will power the Democratic Party after 2017.

On health care, Democratic moderates are being discredited

Democrats have long been divided between two camps on health reform. There are the incrementalists who think, for reasons of both policy and politics, that Democrats need to build on the existing health care system and work with private insurers. And then there are the transformationalists, who think Democrats need to push the United States toward something approximating a single-payer system as closely as possible.

The crucial fact about this divide, however, is that many of the pragmatic incrementalists are philosophical transformationalists: They would prefer a Medicare-for-all system, but they haven’t thought it’s politically possible. Barack Obama is a good example. “If I was starting from scratch, I would have supported a single-payer system, because it’s easier for people to understand and manage,” he told Vox in 2016. But in 2009, after a campaign built on hope and change, he was trying to build bipartisan support for his plan, and if that failed, he needed swing Democratic votes like Nebraska’s Ben Nelson and Connecticut’s Joe Lieberman — and they weren’t going to go for single-payer.

Obamacare was the test of the incrementalist theory, and, politically, at least, it’s failed. Democrats built a law to appeal to moderate Republicans that incorporated key ideas from Mitt Romney’s Massachusetts reforms, and it nevertheless became the single most polarizing initiative of Obama’s presidency. All the work Democrats did to build support from the health care industry has proven to be worth precious little as Republicans push their repeal plan forward. And the complex public-private design of the Affordable Care Act left the system dependent on the business decisions of private insurers and left Democrats trying to explain away premium increases they don’t control. The result is a Democratic Party moving left, and fast, on health care.

“I have been in contact with a lot of Democrats in Congress,” says Yale’s Jacob Hacker, who is influential in liberal health policy circles, “and I am confident that the modal policy approach has shifted pretty strongly toward a more direct, public-option strategy, if not ‘Medicare for all.’”

Obamacare’s defenders argue that the law has worked well in most states and could be easily improved and fortified. They’re right. The core flaw of Obamacare is the subsidies are too low and the individual mandate is too weak. More subsidies, and some tweaks to the insurance regulations, would do the system a lot of good.

If Hillary Clinton had won the election, that’s likely what would have happened — if Democrats even went that far. The party was exhausted by the Affordable Care Act fight, and wanted to move on to other issues like universal pre-k. But if Republicans leave Obamacare gutted and the political arguments that led to it in ruins, there’s not going to be a constituency for rebuilding it when Democrats win back power.

Instead, they’ll pass what many of them wanted to pass in the first place: a heavily subsidized buy-in program for Medicare or Medicaid, funded by a tax increase on the rich. A policy like that would fit smoothly through the 51-vote reconciliation process, and it will satisfy an angry party seeking the fastest, most defensible path to restoring the Affordable Care Act’s coverage gains.

This is a very different vision than the Affordable Care Act ultimately offered. The Obama administration’s hope with their law was to create private insurance marketplaces that eventually became the coverage option of choice for most Americans. Democrats' hope with a program based on Medicare buy-in would be that Medicare becomes the coverage option of choice for most Americans. It might not be full single-payer, but it’s a lot closer than where Obamacare was headed.

The Republican position on health care is unsustainable

One thing we have learned during the Republican Party’s repeal-and-replace process is the true bottom line of GOP health policy, and it’s this: Money currently being spent to buy insurance for the poor should be redirected to tax cuts for the rich. That is, at its core, what the American Health Care Act does — it moves $600 billion from insurance subsidies to tax cuts — and there’s no sign the Senate bill will be different on this score.

The problem is this is a horrifically unpopular health policy. A Quinnipiac University poll released Thursday found only 20 percent of voters approve of the Republican bill. Republicans might be able to pass this proposal, but they can’t protect it afterward. There’s a reason the Senate health bill is being written in a closed-door process with no planned public hearings or serious debate. The hope is to finish it fast and move on forever, as the GOP knows defending it publicly is a losing proposition.

Republicans control the House, the Senate, and the presidency. No one can stop them from passing a bad health care bill if they want to. But they should think carefully about what is likely to come next. Tens of millions of people losing insurance, and they’re to blame. A radicalized Democratic Party with a discredited moderate wing. The end of the assumption that a hybrid public-private model will fare better in America than a government-run system. And all this amid a presumption that sweeping health reform should be done, from the start, in the 51-vote reconciliation process, where expanding government programs is easier than regulating private insurance markets.

Mitch McConnell may prove the best friend “Medicare for all” ever had.