Here is my view, I think that this is extremely unprecedented and wrong to ban Tik Tok, but, it looks like legally, it can be done, whether I don’t believe that Banning Tik Tok would violate the first amendment, The first amendment says: “Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.” I don’t see how banning tik Tok would “abridge the feedom of speech”, because anybody can still post what they think on Facebook, Twitter, or Instagram instead of Tik Tok, so I think that any such ban would be legal. If Tik Tok was a US company, then Trump would not be able to shut them down, because their are other sections of the Constitution that protect against that, but since Tik Tok is a foreign company, those other sections do not apply fully. Also, Article 1 Section 8 of the constitution says, “[The Congress shall have Power] To regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes”, and through the International Emergency Economic Powers Act
Congress has delegated this authority to the president, and it " may be exercised to deal with any unusual and extraordinary threat, which has its source in whole or substantial part outside the United States, to the national security, foreign policy, or economy of the United States, if the President declares a national emergency with respect to such threat." So it looks like the president does have the authority to do this. He could argue in his executive order that Tik Tok presents a threat to national security, and he could issue a national emergency in response to China’s rising power in the International community. However, I don’t really know how he plans to actually attempt to enact this ban, but it would probably fail if it is a sloppily done as his attempt to reverse DACA. If his staff manage to write the order properly, then I would image that it would succeed. Trump could also add ByteDance (Tik Tok’s parrent company to the commerce departments entity list, which would prevent US companies from doing business with them. This method was used agains Huawei, and it has prevented them from using the latest version of Android on their phones, and it stood up in court. I don’t know what he is trying to achieve here though, a lot of people like Tik Tok, and an election is coming up, I can’t imagine that this will earn him much votes, in fact, he will probably lose votes over this. I personally would not mind too much if Tik Tok was banned, I don’t like the short form video format, and I don’t use the app, so I would not be affected by it. I do want to say though that if Tik Tok was bought by an American company, and I have heard that Microsoft is interested, then this would clearly be unconstitutional under the Due process clause of the 5th amendment (which does not apply fully to foreign companies.) Of course, the courts may not agree with my view of the situation and the laws surrounding it, and this ban will probably be challenged in court.