The Supreme Court on Friday was divided over the constitutionality of a federal law that would require social-media giant TikTok to shut down in the United States unless its Chinese parent company can sell it by Jan.

The lawyer for TikTok and its Chinese parent company ByteDance offered a warning during Supreme Court arguments over a law that would compel the sale of the short-video app or ban it in the United States: If Congress could do this to TikTok,