A Dec. 14 ruling on the Affordable Care Act from a federal judge in Texas struck down the law as unconstitutional, and while many legal experts are expecting the ruling to be overturned, a repeal of the sweeping health-care legislation would kick many off their insurance in Washington state.

The ruling came from U.S. District Court Judge Reed O’Connor, in which he stated that since penalties for not having insurance were removed by Congress, the entire Affordable Care Act (ACA) should be repealed. While legal experts have been quoted in media outlets across the country as saying the ruling will likely be overturned, it marks the latest in a push from conservative political politicians and activists to repeal the ACA.

In response, Washington Insurance Commissioner Mike Kreidler issued a statement and California’s Attorney General filed a brief in federal court challenging the judge’s ruling. “This ruling cannot stand. It is cruel and literally threatens the lives of many. I will work with our state and congressional partners to fight this ruling and ensure that all Americans do not lose the protections they currently enjoy under the Affordable Care Act,” Kreidler’s statement read.

O’Connor’s ruling did not come with an enforcement injunction, meaning enrollment for 2019 was able to proceed as planned. Ingrid Ulrey, Public Health Policy Director for Seattle and King County, said it had no measurable impact on enrollment. The appeals process will likely be a long legal road, but it could ultimately make its way to the Supreme Court. Even then, overturning the ACA may be unlikely. “That would be a major decision on behalf of the Supreme Court to overturn legislation that would impact the lives of millions of Americans,” Ulrey said.

On the line are numerous protections for individuals purchasing their own insurance independent of their employers, people with pre-existing conditions, and Medicaid expansions like Washington’s Apple Health program. If the ACA was repealed, insurance companies would be free to limit how much they would pay, deny coverage for conditions, and place caps on their spending, said Steve Valandra, spokesperson for the Washington state Insurance Commissioner’s office.

Maternity coverage, mental health, contraceptive services, vaccinations, and children’s exams could also be on the chopping block. Additionally, Apple Health’s funding comes mostly from the federal government. If the ACA was repealed, its coffers could dry up. “We’d go back to the way things were before, when the insurance companies pretty much had a free reign to do whatever they could,” he said.

Locally, the ACA has dramatically reduced the number of uninsured people in King County, Ulrey said. Before the ACA began in 2013, around 16 percent of the county’s residents were uninsured, a number which has been roughly halved over the last five years. As of the end of open enrollment for 2019, Ulrey said 84,500 people had enrolled through Washington state’s healthplanfinder website. Additionally, Ulrey said, around 135,000 adults in King County are enrolled in the Apple Health program made possible through the ACA expansion. The ACA also allows parents to keep their children on their health insurance until they turn 26—another requirement that could disappear with a potential repeal. According to the state’s Health Benefit Exchange fall 2018 report, nearly 1.5 million people accessed health insurance through Washington Apple Health across the state.

Even if the ACA is repealed, Ulrey said, she’s seen a shift over the past decade in the country’s understanding of health care as a basic human need which everyone should have access to. Once they’ve made the shift to a new system like the ACA where fewer people are excluded, she said, it can be hard to turn back the clock. “We’ve come a long way in the U.S. towards solving these issues, even though they’re complex and difficult to solve,” Ulrey said.

Allison Hoffman, a health-law expert and professor at the University of Pennsylvania, said while it is hard to predict how the Fifth Circuit court of appeals will rule, it is unlikely they will side with O’Connor in throwing out the ACA. If they rule against O’Connor and their decision is appealed, the case could make its way up to the U.S. Supreme Court. Even still, Hoffman said the Supreme Court in the past has preserved the ACA and likely would not overturn it. “There is a scenario in which that could happen, but it would take the Supreme Court changing composition from where it is now,” she said.

Even if O’Connor’s decision is successfully overturned, Hoffman said legal challenges and other attempts to chip away at the ACA after Congress failed to repeal and replace it in past years may be destabilizing the health-care and insurance markets. These impacts on people and states may be greater than the effects of a single legal challenge. And if the ACA was repealed, it would place a divided Congress in charge of finding a fix for the U.S. health-insurance market. “In the short term it would wreak havoc, and then it would put pressure on Congress to fix it,” she said.

While conservatives in the U.S. are pushing to repeal the ACA, a newly energized left has been organizing for single-payer health care. The Democratic Socialists of America, who now have two Congress members following November’s elections, have been pushing nationally and at the local level for Medicare for All. This would create a public health-care system in which services would be funded by the government, eliminating the need for private insurance. Others, including Washington state Rep. Pramila Jayapal (D-Washington) have introduced bills designed to let states create their own single-payer systems. This would allow states to form their own health-care systems and negotiate for lower prescription-drug prices through regulation and raw purchasing power.

Correction: A previous version of this story referred to Apple Care as a Medicare expansion, it is actually part of a Medicaid expansion.