Former President Donald J. Trump posted a video on Monday afternoon that features images of hypothetical newspaper articles celebrating a 2024 victory for him and referring to “the creation of a unified Reich” under the headline “What’s next for America?”

The 30-second video, which Mr. Trump posted on his social media site, Truth Social, features several articles styled like newspapers from the early 1900s — and apparently recycling text from reports on World War I, including references to “German industrial strength” and “peace through strength.” One article in the video asserts that Mr. Trump would deport 15 million migrants in a second term, while text onscreen lists the start and end days of World War I.

Another headline in the video suggests that Mr. Trump in a second term would reject “globalists,” using a term that has been widely adopted on the far right and that scholars say can be used as a signal of antisemitism.

The Trump campaign said in a statement that the video had been posted by a staff member while Mr. Trump was in his criminal trial in Manhattan. The video was still up on his account late Monday night, and his campaign did not respond to a question about why it had not been taken down.

“This was not a campaign video, it was created by a random account online and reposted by a staffer who clearly did not see the word, while the President was in court,” Karoline Leavitt, a campaign spokeswoman, said in a statement. “The real extremist is Joe Biden.”

Mr. Trump has repeatedly denounced Jews who vote for Democrats, accusing them of hating their religion and Israel. In one video this month, he said that “if Jewish people are going to vote for Joe Biden, they have to have their head examined.”