The HealthCare.gov website is photographed in Washington, Oct. 31, 2018. Credit: Pablo Martinez Monsivais | AP

In many ways, the Affordable Care Act is in good shape this year. Democratic gains in the midterm elections mean repeal is off the table for now, and individual insurance is cheaper in some states for the first time in years.

But with just a few more days to sign up for 2019 coverage in many states, enrollment is way down. That’s to be expected to some extent given the end of the individual insurance mandate. But the market needs whatever final push its supporters can manage to shore up the system. If the administration has its way, next year could be worse.

It would be surprising if enrollment were up or even flat. Low unemployment and state Medicaid expansions undoubtedly dampen individual market enrollment. Lower premiums aren’t a pure boost for enrollment because they can also lead to reduced subsidies for lower income Americans. In addition, on top of past cuts to advertising and other support funds, the Trump administration is pushing cheap and skimpy short-term plans that may siphon people from the exchanges.

But the shortfall appears to be particularly broad and deep. Enrollment is down even in states that have made extra efforts to counteract the loss of the federal mandate and bolster exchanges, like New Jersey and California.

One strong possible contributor is Americans’ limited attention span. Last year, the debate over the tax bill that ended the individual mandate was raging throughout the open enrollment period. It was a threat to the exchanges, but any publicity is good publicity.

The need for an enrollment push is more acute this year with the mandate actually set to lapse for the first time. But the ACA isn’t in the news. Attention is being hoovered up by White House turmoil and rocky markets. A lot of the funding and attention that went to pushing enrollment last year was absorbed by particularly expensive midterm elections.

An analysis by liberal media watchdog Media Matters found little TV coverage of open enrollment this year. That’s an issue when most Americans don’t even know when the enrollment period ends. (It’s Saturday, in most states.)

Enrollment usually surges in the last week, but it will be tough to catch up. That’s not great news, but it’s probably not a disaster; insurers knew this was coming and still saw fit to enter new markets and moderate prices.

Still, if the shortfall is worse than insurers anticipated, the market’s hard-won stability could erode. The Trump administration seems to want to help any chaos along. In addition to supporting a potentially damaging lawsuit, the administration is targeting the one thing keeping the market afloat — the ACA’s scaling subsidies for low-income Americans.

The majority of ACA enrollees receive subsidies that are benchmarked to the cost of plans in their states. That’s the reason enrollment has stayed as high as it has through a series of premium-boosting market shocks. The Trump administration recently suggested that states could apply for a waiver that would allow these subsidies to be used for cheaper plans that don’t comply with the ACA.

It’s unclear whether such a waiver passes legal muster or whether states would be interested. But it’s a disastrous prospect for people with pre-existing conditions because it would vacuum healthy people out of the market and send prices for ACA-compliant plans spiraling out of control.

Even in the absence of a repeal effort, it will be a difficult year for the ACA. As tempting as it is to bask in a midterm victory, supporters of the law shouldn’t rest easy, particularly for the rest of this week.

Max Nisen is a Bloomberg Opinion columnist covering biotech, pharma and health care. He previously wrote about management and corporate strategy for Quartz and Business Insider. The ACA open enrollment period in Maine ends Dec. 15.