AMNA NAWAZ: The U.S. Supreme Court heard arguments today in the latest challenge to the Affordable Care Act that could upend a key provision, at issue, the constitutionality of a task force that recommends what preventive care treatments should be covered by private insurance with no cost to patients.

And it could have wide-ranging impacts on everything from cancer screening to HIV prevention medicine to counseling for expectant mothers.

Following it all is Amy Howe, co-founder of SCOTUSblog.

Good to see you again, Amy.

AMY HOWE, SCOTUSblog.com: Thanks for having me.

AMNA NAWAZ: So before we jump into the details of the case, just remind us who's behind this case and how did it end up before the Supreme Court?

AMY HOWE: So the plaintiffs in this case are a couple of individuals and a couple of businesses who object to the requirement that health insurers provide coverage at no cost for what's known as PrEP, pre-exposure prophylaxis medicine, which are medicines that can help prevent the spread of HIV and are highly effective at doing so.

They have religious objections because they say that these medicines encourage same-sex relationships and intravenous drug use.

So they went to federal court challenging the requirements, arguing, among other things, that the structure of this task force violates the Constitution's Appointments Clause, which requires officers of the United States to be nominated by the president and confirmed by the Senate.

And the lower courts agreed with them.

So the Biden administration came to the Supreme Court asking the justices to weigh in.

The justices heard oral arguments today.

The Trump administration is now defending the structure of the task force.

AMNA NAWAZ: So I want to underline that point here.

The Trump administration is now defending part of the Affordable Care Act, also known as Obamacare, after working to undo it for years.

What is their argument?

AMY HOWE: So their argument is that these are what we call inferior officers who don't need to be appointed by the president and confirmed by the Senate, because the secretary of health and human services right now, Robert F. Kennedy Jr., can remove these task force members at any time and exercise control over the task force's recommendations, so that they don't become binding essentially without his saying so.

AMNA NAWAZ: So they're fighting for him to keep the authority to be able to do that with the task force?

AMY HOWE: Exactly.

AMNA NAWAZ: And what is at stake here when it comes to this ruling?

AMY HOWE: Yes.

So, it's -- public health groups are on the same side as the Trump administration in this case, and they say that having these different kinds of medicines and screenings available at no cost has been really important in helping to spread -- stop the spread of all kinds of diseases and promote public health, because they say having these available at no cost really encourages people to get them, that if you take away this no-cost access, the people are much less likely to get these screenings and to take this medicine.

AMNA NAWAZ: And some 150 million Americans have private health insurance in the country too.

So, as you're listening to today's arguments, what stood out to you?

Did you get a sense of which way the justices are leaning on this?

AMY HOWE: It's always difficult.

You want to take these things with a grain of salt to predict based on the oral argument, but it did seem like there was a majority of the justices, including some of the conservative justices like Brett Kavanaugh and Amy Coney Barrett, who seemed inclined to say that these task force members don't have to be nominated by the president and confirmed by the Senate, to leave the task force as it is.

There may be some questions that go back to the lower courts about exactly whether -- some statutory questions and then some questions about what happens to some of the recommendations that the task force made between 2010, when the Obamacare was enacted, and 2023.

And those are not insignificant questions, but the justices right now seemed inclined to rule for the Trump administration and not for the challengers.

AMNA NAWAZ: And we will wait and see, of course.

While we have you, I want to ask you about big issue before the court.

That's the Trump administration's deportation flights.

There was a ruling on Saturday from the court that essentially pauses those flights for now.

But one of the two justices who dissented, that's Justice Samuel Alito, said that the ruling was hastily and prematurely granted.

How do you look at that?

Why did they rule on this now?

AMY HOWE: Well, we don't know for sure, because the justices didn't provide any reasoning for their order.

And that was another thing that Justice Alito sort of lamented in his dissent that came out on Saturday night.

But it seemed like they were concerned about the prospect that detainees could be removed from this Northern District of Texas, and in particular, this Bluebonnet detention facility in Anson, Texas, to El Salvador, or somewhere else, out of the country without the detainees having the kind of notice and opportunity to challenge their removal that the Supreme Court said in an order on April 7 that they were entitled to.

And the detainees' lawyers filed a reply brief today.

And in that reply brief, which was filed around 5:30 this morning, they said, this was not a false alarm.

There is a video and it had been reports that there were, in fact, buses heading towards the airport that turned around after we made our filing in the Supreme Court.

AMNA NAWAZ: Two big cases we know you will keep track of and come back to update us.

That is Amy Howe, co-founder of SCOTUSblog, joining us tonight.

Thank you.

AMY HOWE: Thank you.