But The Caller’s immigration coverage set off intense debates among writers and editors there, reflecting the battle that would soon remake the Republican Party itself. One former writer recalled filing pieces about immigration that would come back from editors with supportive quotes stripped out. Some Caller staff members viewed Mr. Munro’s news articles as little more than opinion columns, with an obvious slant and often factual problems. Mr. Patel, himself an immigrant, pushed editors for more balanced coverage; Mr. Carlson, though, usually defended Mr. Munro’s stories, and plainly agreed with them, as did many of The Caller’s younger employees, former staff members said. On a group email list for editors, one argument culminated in a frustrated message from a longtime editor, Jamie Weinstein, asking whether The Caller now had an official editorial position against immigration.

The Caller had always attracted young writers with more or less conventional conservative politics. But in the years before Mr. Trump declared for president, the site’s free-for-all atmosphere and low barriers to entry also attracted other types — people with short résumés and edgy views on race and American identity. “Whatever sort of was fashionable among smart young conservatives tended to be the trend in the office,” said Jim Antle, a former editor and writer at The Caller. “When The Caller started, most smart young conservatives were libertarian. Within a few years after that, a lot of them were populist, nationalist types — which also meant that they were sometimes attracted to things that were much worse than that.”

‘What We Pretend to Be’

One of the new arrivals was a young Dartmouth graduate named Blake Neff, who joined The Caller in 2014. Mr. Neff, who grew up in South Dakota, was smart but awkward, with a callous streak that most of his colleagues excused as cluelessness. He sometimes complained that women only liked men with looks or money. Once, according to two former Caller employees, he told a colleague she would need to find her future husband before she reached her 30s, then walked over to a whiteboard to chart out the years, months and days she had left. Mr. Neff, who declined to be interviewed for this article, covered education, which mostly meant churning out pieces on far-left professors (“Professor Blames Whites for Her Menstrual Problems”) and strident student protesters (“Hispanic Students at Duke Demand a Nicer Office, Free Trophies”).

Mr. Carlson soon took Mr. Neff under his wing. In August 2015, the two traveled together to the Albany wedding of a Caller colleague. After they returned, Mr. Carlson raved about Mr. Neff’s intelligence. He told others he enjoyed Mr. Neff’s writing style — especially his satires, among them an imagined Trump stump speech about Jesus that Mr. Neff wrote the month after Mr. Trump entered the race. (“I mean, he got out-dealed by Pontius Pilate, a loser if I ever saw one.”) Later, when Mr. Carlson got his own Fox show, he brought Mr. Neff along as a writer. “Anything he’s reading off the teleprompter, the first draft was written by me,” Mr. Neff told his college alumni magazine.

In his downtime, he liked to post on AutoAdmit, an online forum popular with law students, and one of the many digital watering holes where young men egg one another on to be outrageous and offensive. He started one thread titled “Urban business idea: He Didn’t Do Muffin!,” referring to a racist joke that arose on Reddit in the wake of the police killing of Michael Brown in Ferguson, Mo., and he mocked a female acquaintance as an “Azn megashrew,” using a slang term for “Asian.” In 2020, after CNN revealed Mr. Neff as the posts’ author, Mr. Carlson distanced himself, saying they “have no connection” to “Tucker Carlson Tonight.” Mr. Neff’s AutoAdmit posts, however, do not appear to have been a closely kept secret at The Caller. His fellow education writer, Mr. Owens, recalled him bragging about his exploits on the site. “It struck me as, this is just a kid who doesn’t understand why he shouldn’t say this and he’ll grow out of it,” Mr. Owens said.