• President-elect Donald Trump once supported a US ban on TikTok.
• Then, during the 2024 presidential campaign, Trump said he would "save TikTok."
• His cabinet picks might indicate what position he'll ultimately take once in office.

President-elect Donald Trump's views on whether TikTok, which a Chinese company owns, poses a threat to the United States have shifted 180 degrees.

Will they come full circle?

In April, lawmakers concerned about Chinese influence passed a law giving ByteDance, the Chinese owner of TikTok, a deadline of January 19 to sell its social media app to a non-Chinese company or face a nationwide ban. TikTok appealed, but on Friday, a federal court upheld the law, siding with the Biden administration's argument that the service poses a national security threat.

In 2020, Trump unsuccessfully sought to ban TikTok in the United States but has since had a change of heart. During the 2024 campaign, Trump said young people would "go crazy without it." Trump's own TikTok accounts generated millions of views.

Which side Trump ultimately lands on the issue could have a major impact on ByteDance and TikTok, which says it has over 170 million users in the United States. Even if the law is upheld after future appeals, Trump could choose not to enforce it during his presidency.

Trump's closest advisors, however, might have something to say about that. Some of Trump's top cabinet nominees support a TikTok ban.

Sen. Marco Rubio of Florida — Trump's nominee for secretary of state — called a ban a "win for America" earlier this year. Trump's pick for Federal Communications Commission chair, Brendan Carr, also advocated for a TikTok ban in Project 2025, a road map for the first 180 days of a new Republican presidency that the Heritage Foundation, a conservative think tank, published in 2023.

Carr wrote in the plan that TikTok is part of a Beijing "foreign influence campaign by determining the news and information that the app feeds to millions of Americans."

Project 2025 refers to TikTok as "a tool of Chinese espionage" that is "highly addictive" and "especially popular with teenage girls."

"The ties between TikTok and the Chinese government are not loose, and they are not coincidental," the document reads.

John Ratcliffe, the former US director of national intelligence, is Trump's pick for CIA director. Ratcliffe, also an author of Project 2025, told Fox News in 2022 that he thinks TikTok is a "national security threat."

Govs. Doug Burgum of North Dakota, Trump's pick for interior secretary, and Kristi Noem of South Dakota, the president-elect's choice for Homeland Security secretary, both previously banned the app from state-owned devices.

TikTok has denied accusations that it influences content inside the United States or is addictive to children.

A spokesperson for TikTok told Business Insider that the TikTok ban law was "conceived and pushed through based upon inaccurate, flawed and hypothetical information, resulting in outright censorship of the American people."

"The Supreme Court has an established historical record of protecting Americans' right to free speech, and we expect they will do just that on this important constitutional issue," the spokesperson said.