During the 2016 election, Donald Trump promised to repeal and replace the Affordable Care Act. Congressional Republicans tried to make good on this promise in 2017, before a Senate vote effectively killed the effort. In the wake of that failed attempt, Republican states challenged the law’s constitutionality in court, an effort encouraged and aided by the Trump administration.

But with 2020 elections looming, the Trump administration and state-level Republicans have seemingly lost their appetites for slashing and burning the landmark health care legislation.

In briefs filed Friday to the Supreme Court in a lawsuit that seeks to overturn the law in its entirety, the US Department of Justice and a separate group of Republican state attorneys general both asked the court not to take on the case this year.

The case carries heavy implications for the US health care system, and for the 2020 elections as well. Should the Republican plaintiffs succeed in getting the ACA struck down, the Urban Institute estimates that about 20 million people in the US will lose their health insurance. And the result of a Supreme Court ruling could have stark effects on both Democratic and Republican pitches to voters ahead of November’s elections.

The case — Texas v. United States — began in 2018, when Texas (joined by a group of Republican-led states) challenged Obamacare’s constitutionality in federal court, specifically attacking a 2017 update to the ACA which wiped out the individual mandate. Vox’s Ian Milhiser explained the plaintiffs’ argument:

The Texas plaintiffs challenge part of a law that literally does nothing. It requires people who do not have health insurance to pay zero dollars. So no one has standing to challenge the zeroed-out mandate. The plaintiffs claim they get around this problem by pointing to the way the statutory language laying out the individual mandate is structured. Briefly, it’s divided into several subsections. The first says that most individuals “shall” carry health insurance, the second says that people who fail to buy insurance will pay a tax penalty, and the third sets the amount of that penalty — which, again, is now zero dollars. Though the penalty for not having insurance is absolutely nothing, the plaintiffs claim that they are still bound by the language saying that they “shall” carry insurance — and therefore are injured by a law that commands them to do something they don’t want to do.

Judge Reed O’Connor, a North Texas-based federal judge who has ruled in several key conservative cases over recent years, found in favor of the plaintiffs in 2018, ostensibly striking down the ACA, pending appeals. An appeals process did indeed move forward, with the Court of Appeals for the Fifth Circuit agreeing last December that the individual mandate is unconstitutional, but deciding that the case must be sent back to O’Connor for further consideration.

While Trump’s DOJ has sided with the plaintiffs in the case, several Democratic-controlled states and the Democratic-controlled House of Representatives have stepped in to defend the law in court. Following the decision in the court of appeals, Democratic attorneys petitioned the Supreme Court to take up the case on an expedited basis. It was to this petition that Republicans responded on Friday, asking the justices to wait to take up the case.

It may seem odd that Democrats would want a Supreme Court that could well rule to end Obamacare to do so sooner rather than later, and that Republicans would ask it to hold off doing so. But in the context of the 2020 elections, the stances of each party begin to make more sense.

Health care looms large again in the 2020 elections

Studies have shown that Americans — including Republicans — like the benefits the ACA has given them. For example, a 2018 Kaiser Family Foundation study found that 80 percent of Republicans like the ACA’s provision that lowers the cost of prescription drugs for those on Medicare, and that 58 percent of Republicans like that it stopped insurance companies from denying coverage based on preexisting conditions.

Overall, the foundation found that 52 percent of Americans approved of the ACA as of November 2019, and that 56 percent feared they, or someone they knew, would lose coverage if the Supreme Court overturned the law.

Essentially, while the ACA is commonly targeted by the president and his allies in Congress, the law itself is fairly popular, and at least some of its provisions are overwhelmingly popular.

This makes removing it a somewhat dangerous proposition for Republicans, particularly those in Congress that rely on broad bases of support to retain their seats. In the 2018 midterm elections, Democrats worked to exploit the tension between the public’s view of the ACA and GOP lawmakers’, making healthcare a key issue — a strategy seen as being crucial to the Democrats’ eventual victory in retaking the House of Representatives.

Thanks to Texas v. United States, Democrats see an opening for a similar strategy in 2020. If the Supreme Court were to uphold the ACA, Democrats would be able to campaign as the party that defended Obamacare. If it were to be overturned, then Democrats would cast the GOP as the party that dumped 20 million people off their health insurance in an election year.

It is in Republicans’s best interests to avoid that lose-lose scenario, and therefore they have asked the court not to take up the case in the first place.

“The lawfulness of the act is undoubtedly a matter of the utmost national importance, but the current petitions do not justify immediate, emergency review by the court,” said the brief filed by the attorney general of Texas and officials in 17 other states.

The Supreme Court has not yet signaled how it will proceed. It would take just four justices to agree to take the case, and all five of the justices who ruled to uphold the law the last time the ACA’s constitutionality was in question at the court are still on the bench.