Andrew Kaczynski, the BuzzFeed reporter whose scoop about Donald J. Trump’s early support for the invasion of Iraq surfaced in the presidential debate last week, is leaving to join CNN, just a month before the election.
The two other members of BuzzFeed’s political research team, Nathan McDermott and Christopher Massie, and Kyle Blaine, the deputy politics editor, are also going to CNN, leaving BuzzFeed short-handed for the final stretch of the campaign.
The departures, which come only weeks after BuzzFeed said it was formally dividing its news and entertainment divisions, are also likely to resurface questions about the company’s plans for its news operation.
Even by the standards of an industry where turnover is common, the suddenness of Mr. Kaczynski’s move was surprising. Mr. Kaczynski and the three others officially resigned from BuzzFeed on Monday. Andrew Morse, an executive vice president for CNN and head of CNN Digital, said in a telephone interview: “We’re having conversations today. You could make the case that they already started today.”
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.
Mr. Smith praised Mr. Kaczynski on Twitter at the time, saying, “A huge part of this debate is rooted in @BuzzFeedAndrew’s reporting.”
Mr. Morse of CNN said that Mr. Kaczynski and his team had been “on our radar for the last two years” and that they began having discussions in the last few weeks.
Mr. Morse suggested that they made the decision to join CNN very recently. “It started moving very quickly over the last couple of days, and we had some pretty intense conversations over the weekend,” he said.
“There was no question about taking a beat at all,” he added. “The notion was, let’s get them in the door as quickly as possible. And their only question for us: When can we get our computers and when can we get started?”
On Monday, Mr. Smith said in an email: “I guess this means that CNN has seen the value in doing the kind of tough reporting on Donald Trump that BuzzFeed News has been doing all presidential cycle, and we wish Andrew good luck.”