NEW YORK (AP) -- Legislation forcing TikTok's parent company to sell the video-sharing platform or face a ban in the U.S. received President Joe Biden's official signoff Wednesday. But the newly minted law could be in for an uphill battle in court.

Critics of the sell-or-be-banned ultimatum argue it violates TikTok users' First Amendment rights. The app's China-based owner, ByteDance, has already promised to sue, calling the measure unconstitutional.

But a court challenge's success is not is not guaranteed. The law's opponents, which include advocacy organizations like the American Civil Liberties Union, maintain that the government hasn't come close to justifying banning TikTok, while others say national-security claims could still prevail.

For years, lawmakers on both sides of the aisle have expressed concerns that Chinese authorities could force ByteDance to hand over U.S. user data, or influence Americans by suppressing or promoting certain content on TikTok. The U.S. has yet to provide public evidence to support those claims, but some legal experts note that political pressures have piled up regardless.

If upheld, legal experts also stress that the law could set a precedent carrying wider ramifications for digital media in the U.S.

Here's what you need to know.

That's the central question. TikTok and opponents of the law have argued that a ban would violate First Amendment rights of the social media platform's 170 million U.S. users.

Patrick Toomey, deputy director of the ACLU's National Security Project, said a TikTok ban would "stifle free expression and restrict public access" to a platform that has become central source for information sharing.

Among key questions will be whether the legislation interferes with the overall content of speech on TikTok, notes Elettra Bietti, an assistant professor of law and computer science at Northeastern University, because content-based restrictions meet a higher level of scrutiny.

ByteDance had yet to officially file a lawsuit by late Wednesday, but Bietti said she expects the company's challenge to primarily focus on whether a ban infringes on these wider free-speech rights. Additional litigation involving TikTok's "commercial actors," such as businesses and influencers who make their living on the platform, may also arise, she added.

TikTok is expressing confidence about the prospects of its planned challenge.

"Rest assured, we aren't going anywhere," TikTok CEO Shou Chew said in a video response posted to X Wednesday. "The facts and the Constitution are on our side, and we expect to prevail again."

Toomey also said that he is optimistic about the possibility of TikTok being able to block the measure in court, noting that both users and the company "have extremely strong" First Amendment claims.

"Many of the calls to completely ban TikTok in the U.S. are about scoring political points and rooted in anti-China sentiment," Toomey added. "And to date, these steps to ban TikTok had not been remotely supported by concrete public evidence."

Still, the future of any litigation is hard to predict, especially for this kind of case. And from a legal perspective, legal experts say it can be difficult to cite political motivations, even if they're well-documented, as grounds to invalidate a law.

The battle could also string along for some time, with the potential for appeals that could go all the way to the Supreme Court, which would likely uphold the law due to its current composition, said Gus Hurwitz, a senior fellow at the University of Pennsylvania's Carey Law School.

TikTok's legal challenge won't go on without a fight. The government will probably respond with national-security claims, which were already cited prominently as the legislation made its way through Congress.

Toomey maintains that the government hasn't met the high bar required to prove imminent national-security risks, but some other legal experts note that it's still a strong card to play.

"One of the unfortunate and really frustrating things about national-security legislation (is that) it tends to be a trump card," Hurwitz said. "Once national-security issues come up, they're going to carry the day either successfully or not."

Hurwitz added that he thinks there are legitimate national-security arguments that could be brought up here. National security can be argued because it's a federal measure, he added. That sets this scenario apart from previously unsuccessful state-level legislation seeking to ban TikTok, such as in Montana.

But national-security arguments are also vulnerable to questioning as to why TikTok is getting specific scrutiny.

"Personally, I believe that what TikTok does isn't that different from other companies that are U.S.-based," Bietti said, pointing to tech giants ranging from Google to Amazon. "The question is, 'Why ban TikTok and not the activities and the surveillance carried out by other companies in the United States?'"

Still, legal experts note that there could be repercussions beyond TikTok in the future.

The measure was passed as part of a larger $95 billion package that provides aid to Ukraine and Israel. The package also includes a provision that makes it illegal for data brokers to sell or rent "personally identifiable sensitive data" to North Korea, China, Russia, Iran or entities in those countries.

That has encountered some pushback, including from the ACLU, which says the language is written too broadly and could sweep in journalists and others who publish personal information.

"There's real reason to be concerned that the use of this law will not stop with TikTok," Toomey said. "Looking at that point and the bigger picture, banning TikTok or forcing its sale would be a devastating blow to the U.S. government's decades of work promoting an open and secure global internet."