Inside the West Wing, Mr. Trump has decentralized power beneath him, giving as many as a half-dozen White House staffers the ability to report to him directly and go around the chief-of-staff position. As aides were drafting the speech on Wednesday, it was unclear who had authority to approve changes, White House officials said. In some instances it was the vice president’s office. Other aides said they sent changes to multiple senior officials, hoping the edits would be made…

But the speech itself caused a divide inside the White House. Mr. Kushner was among those who thought it was important to deliver an address to calm fears and show the administration’s seriousness. White House counselor Kellyanne Conway advised against it, telling colleagues that it was a terrible idea and the message could be conveyed through a videotaped message that the president could release on Twitter…

The speech was being rewritten up until the time it was fed into the teleprompter, aides said. And there were multiple mistakes. Insurance companies aren’t waiving deductibles for coronavirus treatment, as Mr. Trump read from the remarks. Nor are there exemptions in the new travel ban from Europe for Americans who have undergone health screenings; the ban is on foreign nationals, not Americans. The administration is working on a second parallel policy aimed at screening Americans returning home from abroad.

Mr. Trump then inserted his own costly mistake, according to a review of draft speeches and officials familiar with the process. Instead of saying that the travel ban won’t apply to trade and cargo, Mr. Trump inserted an extra word, saying the prohibitions “will not only apply to the tremendous amount of trade and cargo.”