GEOFF BENNETT: The clock is ticking on a potential ban of the popular social media app TikTok.

In April, Congress and President Biden gave the app's Beijing-based parent company 270 days to find a new owner or face a shutdown, arguing Chinese control of the platform was a national security threat.

The U.S. Supreme Court is right now considering a challenge to the law, but barring any last-minute changes, users will no longer be able to download TikTok starting on Sunday.

For his part, president-elect Trump has pledged to provide some kind of reprieve from the ban.

His national security adviser, Mike Waltz, reiterated that on FOX today.

REP. MIKE WALTZ (R-FL): We will put measures in place to keep TikTok from going dark.

And the legislation allows for an extension as long as a viable deal is on the table.

And then essentially that buys President Trump time to keep TikTok going.

GEOFF BENNETT: We're joined now by Carrie Cordero.

She's a senior fellow at the Center for a New American Security.

Thanks for being here.

CARRIE CORDERO, Former Department of Justice Official: Thanks for having me.

GEOFF BENNETT: So, with this January 19 deadline just days away, it appears members of the incoming Trump administration and bipartisan members of Congress are trying to buy themselves more time.

What are the possible outcomes?

CARRIE CORDERO: Well, the law that they passed last spring doesn't leave a lot of options.

What they really needed, what was in the law, was a credible buyer lined up and a willingness on behalf of TikTok to actually be sold to that buyer.

There's nothing out there right now that looks that that circumstance really occurs.

So the cleanest way for them to give more time for president-elect Trump once he comes into office would actually be, between now and Sunday, Congress passing a new law extending the timeline.

That seems pretty unlikely.

GEOFF BENNETT: And the president-elect, Donald Trump, he at one time supported this ban.

Now he doesn't.

What accounts for that?

CARRIE CORDERO: Well, it's hard to say what changed his mind.

One thing we can look to is his and his campaign's use of TikTok during the campaign.

This law was passed last spring.

Obviously, over the course of the campaign, between then and November, his campaign found that TikTok was useful to them.

Other candidates used it as well.

And so perhaps that's what changed his mind.

Perhaps also it was lobbying efforts on behalf of TikTok or other content users or other stakeholders.

GEOFF BENNETT: What's particular about the case that the Supreme Court is about to rule on?

And how might that affect things?

CARRIE CORDERO: Well, so that would totally change things, depending on which way the court rules.

Based on their oral arguments last week, the indications from the questions that the justices were asking are that the court intends to uphold the law, in other words, keep the divestment ruling in place, and, eventually, if there's no buyer in the next few days, that the app would not be as available as it currently is.

I think there is a legal path for the court to have ruled on First Amendment grounds and to actually rule in favor in TikTok.

But, again, the argument did not indicate that that's the direction the court's going.

GEOFF BENNETT: As we mentioned, the government sees TikTok as a national security threat.

What's the precedent, though, for the federal government banning a social media app?

CARRIE CORDERO: So I think this case really is novel.

The precedent for the government is the fact that this law was crafted as divestment.

And there is a history of the United States using divestment when there is foreign ownership of a company to mitigate national security threats.

What's different about this case is that it is about access to information.

Over 170 million Americans use TikTok, and this law is different because it governs the information space and it applies this divestment to a source of information and a place that Americans communicate, both as individuals and as businesses.

GEOFF BENNETT: In the meantime, people are now downloading and signing up for this other Chinese-owned app called RedNote.

Tell us about that and the potential dangers there.

CARRIE CORDERO: Well, so what happens is that another foreign-owned, in this case Chinese as well, app becomes available.

And so it's not a good outcome of this law that it is actually driving users to another Chinese-controlled or Chinese-influenced app.

So that's a downside.

And that's why I think really, in the long term, although the government made very compelling national security arguments backed up by classified information they provided to Congress, not backed up by much unclassified information provided for the public, but although the government alleges very strong national security concerns, in this case, my assessment is that the law is sort of shortsighted, because it deals with this particular situation and it doesn't really account for the fact that there could be some other foreign-controlled app down the road.

And then how do you handle that?

GEOFF BENNETT: If this ban goes into effect, what might an average user see starting on Sunday?

CARRIE CORDERO: Well, there really is a big question mark because we haven't been in this situation before.

The law itself applies not actually to TikTok.

The law applies to the companies that provide access to it.

So the way it is expected to be implemented is that the app would no longer be available through app stores, for example, for people to download following the 19th of January.

There also would not be further updates to the app.

So basically new users wouldn't be able to access it if the companies do in fact restrict that access and it would become more buggy.

It would not have new content necessarily.

And so there would be sort of a degradation over time.

GEOFF BENNETT: Carrie Cordero, thanks, as always, for your insights.

We appreciate it.

CARRIE CORDERO: OK.

Thanks so much.