The Supreme Court seemed likely to uphold a law that would ban TikTok in the United States beginning Jan. 19 unless the popular social media program is sold by its China-based parent company. Hearing arguments in a momentous clash of free speech and national security concerns,

The court is hearing oral arguments on TikTok’s bid to block a law that would lead to its ban in the U.S. starting Jan. 19 if it isn’t sold by its Chinese owner.

The Supreme Court seemed likely to uphold a new law that could force TikTok to shut down in the U.S., with conservative and liberal justices alike expressing skepticism about the legal challenge.