The moves also leave a void at BuzzFeed, which has built its news reputation on its political coverage and is gearing up for what will probably be a frenetic last month of the campaign. Mr. Kaczynski, 26, who announced he was joining BuzzFeed in late 2011 while still a student at St. John’s University, was among the first hires on the news side. Under Ben Smith, a star political reporter at Politico before joining BuzzFeed as editor in chief, Mr. Kaczynski and a team of reporters aggressively covered the 2012 presidential race, elevating the company’s reputation and drawing respect, some of it grudging, from established news organizations.

The departures could also feed the apparent feud between Jeff Zucker, the president of CNN, who recently said he did not think BuzzFeed was a “legitimate” news organization, and Mr. Smith, who said that CNN had given too much airtime to Donald Trump in the interest of ratings.

Mr. Kaczynski declined to be interviewed and referred questions to CNN. But in an interview with The Huffington Post, which first reported the moves, Mr. Kaczynski said: “To be at the biggest name in news for the last month of what has been the craziest election in modern history is just a great opportunity for me and everybody on our team.”

During this campaign, Mr. Kaczynski and his team have published attention-grabbing articles, including one last week about Mr. Trump’s appearance in a Playboy video from 2000.

In February, Mr. McDermott and Mr. Kaczynski wrote an article about a 2002 interview with Howard Stern during which Mr. Trump said he supported the invasion of Iraq. Mr. Trump has repeatedly said that he opposed the Iraq War, an issue that has come up frequently during the campaign. Mr. Trump mentioned the interview during the presidential debate last week, saying the interview showed he was right.