By Alexis Keenan and Ben Werschkul

President Donald Trump issued an executive order on Monday aimed at temporarily shielding TikTok from a US ban as part of a flurry of activity on his first day back in office.

The executive order, which experts have said is legally dubious, opens a 75-day window for the Trump administration "to determine the appropriate course forward in an orderly way" for TikTok's US business after a new law effectively banning the app took effect at midnight on Sunday.

Trump based his authority for the order on his "unique" responsibilities as president, stating in the directive that the timing of the law "interferes with my ability to assess the national security and foreign policy implications of the Act’s prohibitions before they take effect."

"This timing also interferes with my ability to negotiate a resolution to avoid an abrupt shutdown of the TikTok platform while addressing national security concerns."

The law that briefly resulted in TikTok's shutdown doesn't outright ban the app, but rather it prohibits users from accessing the platform through app stores — like those run by Apple (AAPL) and Google (GOOG, GOOGL) — and cloud services unless parent company ByteDance sells itself to an owner that is not controlled by a country the US considers adversarial.

Speaking with reporters in the Oval Office on Monday evening, Trump reiterated the idea of the US taking a 50% stake in a joint venture to continue running TikTok. The president also floated the idea of imposing tariffs on China if they don't approve a proposed buyer for TikTok's US assets.

Trump told reporters TikTok may be worth $1 trillion.

Trump initially laid out plans for the order on Sunday amid weekend drama over TikTok's fate in the US. TikTok went dark late Saturday into Sunday, but following assurances from Trump that same day, TikTok started restoring its service after a 12-hour shutdown.

Many on Capitol Hill — not to mention outside experts — questioned whether Trump has the authority to make good on those promises.

Some of Trump’s closest political allies are the most outspoken critics of TikTok, and have so far stood by the law that they passed last April with strong bipartisan margins.

In a statement early Sunday, Republican Sens. Tom Cotton and Pete Ricketts said, "now that the law has taken effect, there’s no legal basis for any kind of 'extension' of its effective date." Cotton added earlier this week on the Senate floor that "there will be no extension, no concession, and no compromises for TikTok."

House Speaker Mike Johnson, another top Trump ally, also raised questions Sunday, telling NBC he wanted to see the current law enforced and that he is "really heartened to see that Google and Apple and Microsoft have taken the steps to comply with the law."

The back-and-forth between Trump, TikTok, and US lawmakers will remain a focus during the early days of his presidency.

TikTok CEO Shou Zi Chew, as well as US Big Tech CEOs, Apple's Tim Cook and Google's Sundar Pichai, whose companies are tasked with implementing the US ban against TikTok, were in attendance at Monday’s inauguration events.

As of Monday, TikTok remained unavailable on the Apple App Store and on Google Play.

A Truman-era precedent

An executive order has only a "narrow chance" of protecting TikTok from the force of the Protecting Americans from Foreign Adversary Controlled Applications Act, which gives ByteDance, TikTok’s parent company, an ultimatum to divest its ownership of the platform or face a nationwide ban.

"Under current Supreme Court precedent, an executive order is on very shaky ground," Kent Law School professor, Mark Rosen, told Yahoo Finance last week. Rosen explained the high court has invalidated orders that contravene federal law I large part because they fly in the face of the checks that Congress and the judicial branch are supposed to place on executive power.

The main precedent that makes a Trump executive order an unreliable safe haven for TikTok comes from a limitation on presidential power established in the landmark 1952 Supreme Court case titled Youngstown Sheet & Tube Co. v. Sawyer.

Subsequent courts have been reluctant to identify independent, exclusive presidential authority that conflicts with law, Rosen said, because it risks vesting the president with "king-like" power.

In that case, the court struck down an executive order issued by President Harry Truman directing the US Commerce Department to take over the nation’s steel mills.

Truman’s order purported to keep a labor strike from threatening US steel protection during the Korean War.

Despite that claim, the court ruled the president lacked the power to overtake private property, even during a time of war.

Still, Rosen said, several Supreme Court justices, including the Chief Justice John Roberts have appeared sympathetic to an emerging "unitary executive theory," which suggests that the president holds sole authority over the entire executive branch.

That potential change in doctrine, he said, could open the door for Trump to argue the order is permissible.

Ben Werschkul is Washington correspondent for Yahoo Finance.

Alexis Keenan is a legal reporter for Yahoo Finance. Follow Alexis on X @alexiskweed.

Source: Yahoo finance