If the Centers for Disease Control and Prevention decides, the Biden administration will appeal the Florida judge's ruling that struck down the federal mask requirement.

The announcement from the Department of Justice came after a day of back and forth inside the White House, as administration officials faced a legal and political quandary: whether to let the judge's ruling stand or to fight it, knowing that an appeal could result in a higher court.

In the end, the administration put off a decision on whether to contest the ruling. The C.D.C. and the Justice Department disagree with the district court's decision and will appeal.

Lawrence O. Gostin is an expert in public health law at Georgetown University.

C.D.C. is going to be gun-shy about this judge's decision if you let it go forward.

The mask mandate, which applied to transportation hubs like airports and train stations, and even to ride-sharing services like Uber, had been set to expire on May 3, even before the judge struck it down on Monday.

The Justice Department will file an appeal if the C.D.C. decides there is a public health basis for trying to extend the mandate. If the C.D.C. decides not to appeal, the case will end without any signal of the executive branch agreeing to the judge's view of its authority.

The Justice Department continues to believe that the order requiring masking in the transportation corridor is a valid exercise of the authority Congress has given C.D.C.

The president directed the C.D.C. to impose the mandate. The agency extended it again on April 13. It wanted to keep the requirement in place for several more weeks while it assessed the severity of the Omicron subvariant known as BA.2 which recently became the dominant version among new U.S. cases.

White House officials, including President Biden, were cautious in their public remarks as the administration considered its options. On a trip to New Hampshire to promote infrastructure spending, the president was asked by reporters if people should wear masks on planes.

Mr. Biden replied that it was up to them.

The judge who struck down the mandate put forward a sharply constrained interpretation of the legal authority of the C.D.C. The agency would be tied up in future public health crises if her view prevailed.

A district court judge's ruling is not a binding precedent. The agency's future conduct could be in danger if she appealed the matter to the Court of Appeals for the 11th Circuit in Atlanta. Most of the judges on that circuit are appointees of the president.

The Supreme Court has a conservative majority. In January, it blocked a Biden administration order that large employers require workers to get vaccinations. The court upheld a federal mandate requiring health care workers at facilities receiving federal money to be vaccine free.

The C.D.C. has very little regulatory authority, according to Dr. Thomas Frieden, who directed the C.D.C. for eight years under President Barack Obama.

There is a risk that by pushing the envelope on other issues, we could be in violation of the law.

The mask mandate's supporters have viewed an appeal as risky.

The bigger issue is that you need to reserve the ability for the C.D.C. to act in case we have a big outbreak in the fall.

If you end up in the Supreme Court, you could really damage your ability to respond to the epidemic in the future.

Others spoke in favor of an appeal.

Rich Besser said that he was worried that the judge was saying that C.D.C. doesn't have the authority to protect the health of people in America.

As a matter of politics, support for mask mandates has fallen in opinion polls as it has become clear that healthy people who have been vaccinations and boosted, as well as those who remain unvaccinated but have survived a bout of Covid-19, are the ones who support the mandates.

The country clearly wants to move on, according to David Axelrod, a Democratic strategist who served as senior adviser to President Barack Obama. The path of least resistance would be to stand down because the clock is running out.

Some people are in favor of mandates. They pointed to the fact that very young children are not eligible for vaccine because they are less likely to experience significant symptoms, as well as the continuing serious risk that any infection poses to immunocompromised people.

Two senior officials in the White House said Monday's ruling surprised and frustrated them. On Tuesday, as travelers aboard airplanes took directions from pilots, and riders aboard transit systems went mask-free, the Biden administration did not lay out a detailed plan to contest the ruling, even as public health experts warned that the C.D.C.'s authority was questionable.

The most recent extension of the mask mandate was reasonable, to give officials time to assess the evidence and make a decision about whether to continue it.

The scientists asked for 15 days to make a more data-driven decision. I will follow CDC guidance and wear a mask on planes.

The reporting was contributed byKatie Rogers.