Alan Diaz / Associated Press

Federal open-enrollment season rarely, if ever, seems to go smoothly. In 2017, President Donald Trump’s administration cut the budget for Affordable Care Act advertisement by 90 percent, and slashed the window to sign up for new health-insurance plans by 15 days. In a scramble to counter those rollbacks, former President Barack Obama himself had to cut an ad promoting his signature policy achievement.

The year before that, misinformation and anxiety proliferated in advance of then-President-elect Trump’s promises to repeal Obamacare. And even before that, the annual sign-up season wasn’t too far removed from catastrophic glitches and poor recruitment among young adults. All those disturbances are reminders that while the bulk of the massive Affordable Care Act is the law of the land, it is still a rather delicate experiment.

This year’s open enrollment was no different. The window, which ended at midnight Pacific time on the night of December 15 for most states, was marked by the same old disorder, as well as by the loss of the individual requirement to purchase insurance—which Congress essentially repealed in 2017, effective in 2019. But the biggest disturbance came right at the end, when on December 14 a federal judge ruled that the entire law was unconstitutional. Anybody still considering signing up for insurance during open enrollment was faced with a number of uncertainties. What does the ruling mean, and will Obamacare even still be around to cover people in the future?

The ruling probably comes as a shock to voters, who just experienced the first election cycle in almost a decade when Republicans didn’t necessarily run with a promise to repeal Obamacare. In fact, Republicans often ran on vague promises to “protect” preexisting conditions, and ballot initiatives to expand Medicaid picked up traction across the country, even in deep red states. In 2018, across the political spectrum, voters came out in favor of the law.

Yet even as the GOP campaigned on a more ambivalent position regarding the substance of the Affordable Care Act, much of the Republican brain trust and the Trump administration were involved in another concerted effort to dismantle the entire law. In a lawsuit joined by 19 Republican-led state governments, Texas prosecutors argued that because Congress removed the penalty for failure to purchase insurance—in essence, voiding one of the pivotal pieces of the Affordable Care Act—the rest of the intricate pieces of policy in the law that depend on that provision must also be voided.

Instead of defending the law, the Trump Justice Department agreed with a good portion of that analysis in briefs. On Friday, district court Judge Reed O’Connor agreed with the plaintiffs’ argument, saying that the act “can no longer be sustained as an exercise of Congress’s tax power,” and that since he could not go through the bill and find out which pieces could be severed safely, the entire law must be thrown out.

That argument was always considered far-fetched, and for both people seeking insurance and those keeping score on the political side, the upshot is: It still probably is. O’Connor’s decision rests on three fundamentally controversial and perhaps tenuous interpretations of the law that may be rejected as the case is considered in the Fifth Circuit Court of Appeals, or by the Supreme Court, should it get that far.

The first is whether the plaintiffs even had standing to file a suit. According to a press release from the American Medical Association, which filed a brief in favor of the ACA, “The plaintiffs do not have standing because they have not suffered any real, concrete injury. They do not have to pay a penny in tax if they choose not to obtain health insurance. That unavoidable fact makes clear that the plaintiffs simply seek to change the federal government’s health care policy through the courts, rather than through the legislature.”

The second issue is whether Congress even repealed the individual mandate provision at all. Since Republicans in the Senate this year could not put together a filibuster-proof majority, they used a procedural move related to Congress’s tax powers to zero out the tax penalty for the individual mandate, a move that required only a majority vote. Under that “reconciliation” provision, Congress cannot make major policy changes, but can change items that relate to the budget. The ACA’s defenders claim that this move did not actually remove the mandate, but just made the penalty zero dollars.

The third issue before Judge O’Connor was the matter of whether the constituent pieces of the Affordable Care Act are “severable,” even if Congress did invalidate one piece of it. The principle of severability dictates whether courts can strike down whole laws if pieces of them are removed by legislation. According to Jonathan H. Adler and Abbe R. Gluck, two law professors, in an op-ed in The New York Times, “The principle presumes that, out of respect for the separation of powers, courts will leave the rest of the statute standing unless Congress makes clear it did not intend for the law to exist without the challenged provision.” In the view of pro-ACA lawyers, Congress’s very choice to pursue reconciliation indicates that the body did not intend to strike down the entire ACA at all.

For the immediate and near-term future, all this means that nothing much is changing for Obamacare. O’Connor did not issue an injunction against any part of the law, likely expecting an appeal and stay from the Democratic state attorneys general defending the ACA. Really, as the lawsuit barrels toward the higher courts and as partisan battle lines are drawn around it, the resolution to this drama could be far off, meaning most of the uncertainty is in the future.

But as the past few years have illustrated, future uncertainty is a key shaping agent of how such a complicated law plays out today. As predicted, open enrollment this year started out weak, with the federal healthcare.gov portal reporting a 12 percent drop-off in sign-ups through December 8.

While some of that drop-off is likely good news to some ACA advocates, since it reflects the spread of the Medicaid expansion to several states, part of the drop-off is undeniably connected to the loss of the individual mandate and the atmosphere of confusion that emanates from the White House. Especially for younger, healthier participants, Obamacare marketplaces rely on late surges to make a good deal of the final volume of sign-ups. With an adverse, complicated decision coming on the eve of the deadline, it’s unclear whether that traditional surge came through.

As a consequence, some Democratic officials are lobbying for an expansion of open enrollment. New Jersey Governor Phil Murphy called on “the Trump administration to extend this year’s enrollment period to allow us the chance to do just that, and to make it clear that the Affordable Care Act and its protections remain the law,” citing “disarray” from O’Connor’s decision as a reason.

Of course, the “disarray” suits President Trump, who has made it clear since his inauguration that both official attempts to repeal the law and bureaucratic efforts to derail it are wins for his priorities. In the wake of the loss of the individual mandate and chilled open-enrollment numbers, O’Connor’s decision itself—regardless of its chances in higher courts—is a victory for Trump. In the absence of the legislative or even popular will to repeal Obamacare, maximizing chaos will do just fine for Trump’s agenda.

The evidence available indicates that the chaos is degrading Obamacare and is negatively affecting people’s ability to find affordable coverage. Despite a strong economy that has buoyed Trump politically and reduced poverty, in 2018 the number of uninsured children rose. That’s not a small deal. Even beyond the Affordable Care Act, one of the less ambiguous public-policy triumphs of the past 50 years has been the precipitous and steady decline in uninsured children, a decline essentially broken only by the Great Recession of the past decade. This spike is an omen that could shape the health-policy landscape in years to come.

For now, if only through inertia, Obamacare persists. It is a true policy juggernaut, one that has survived a concerted effort to repeal it that spawned one of the strongest Republican-wave elections in history and two years of spear-brandishing from conservatives when they seized control of every lever of federal power in 2016.

It has grown from a controversial law that broke up dinner parties and bipartisan friendships to a background feature of American life that most people just accept as an overall positive layer of the bureaucracy. The ACA, at this point, is perhaps too big to be taken down in a single blow, as the GOP intends to do in Texas v. Azar. But, as Trump knows, with enough effort it is certainly not too big to fail.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.