"The most important thing is that we are ultimately successful," said Kentucky Gov. Andy Beshear. "While I want to move with speed, the ultimate priority is protecting health care, and I'm in this fight for as long as it will take."

North Carolina Attorney General Joshua Stein said he didn't "want to get hung up on dates," as the deadline for asking the high court to consider a case this term approaches quickly. The justices generally stop adding cases to the argument in January.

"I can't think of a reason why we wouldn't want to seek cert, but we need to deliberate," Stein told reporters.

The hesitation reflects the political realities of the coalition comprising 20 states and the District of Columbia that is defending the Affordable Care Act.

Challenging Trump administration initiatives in court has become routine for Becerra, who is backed by Democratic supermajorities in both legislative houses, a Democratic governor and Democrats who control every statewide office. That's not the case for Beshear, Stein or Michigan Attorney General Dana Nessel, who was also on Thursday's call.

The debate also acknowledges the political—and legal—gamble at play. If the Supreme Court takes up the case in 2020, it could add fuel to the national debate over health care, a top issue among voters, before the presidential election. Or it could mean a speedy demise for a program that has extended health care coverage for millions of Americans.

The Fifth Circuit's decision "did President Trump and Republicans a big favor and sent the case back down to the same judge and in so doing all but ensured that there would be no ruling on the law's fate until after the 2020 election," Abbe Gluck, a Yale law professor, said in a piece at The New York Times. "The court has enabled Mr. Trump to escape accountability to the voters for his efforts to destroy the law."

Gluck, who has written extensively on the ACA, called Becerra's push to quickly get the Supreme Court to review the appeals court ruling a "long shot."

Supporters of the Affordable Care Act rally at the US Supreme Court. Photo: Diego M. Radzinschi / ALM

The appeals court on Wednesday said the Affordable Care Act's individual mandate is unconstitutional, upholding a declaration from a Texas trial judge. The appeals court, however, stopped short of declaring the entire law unlawful, as the trial court did. The three-judge panel sent the dispute back to the district court for a do-over on whether the individual mandate can be severed from the rest of the law.

Trump's Justice Department initially said the mandate could be severed, but then the government went further and fully embraced the Texas court's complete knockdown of Obamacare.

"The Trump administration has changed its position on the severability issue several times, making it a necessity for the lower court to review the provisions of the ACA that have nothing to do with coverage," Stephanie Kennan of McGuireWoods Consulting said in a statement. "This, however, delays the opportunity for the Supreme Court to take up the case, meaning the uncertainty about the law's future continues and will not likely be settled before the election."

Nessel, the Michigan attorney general, told reporters she is not confident the Supreme Court would immediately take the case.

"I would be surprised if they wanted the district court to rule on it before it went back up the chain," she said.

Becerra noted that the high court moved quickly this year to hear a challenge to the Trump administration's plan to add a citizenship question to the 2020 census. On a 5-4 ruling, the court ruled in June that the question could not be included, calling the U.S. Commerce Department's arguments for doing so "contrived."

"This is late in the session for the court to be taking up cases," Becerra acknowledged, "but this is a critical one."

Read more: 

• 6 ways states are preparing if the ACA is invalidated
• State ACA reporting compliance: What employers need to know now
• More than half of American families could feel the impact if the ACA is overturned