“I just no longer felt comfortable with the programming at Fox.”

“I’m fine with opinion: conservative opinion, liberal opinion,” Mr. Wallace said in his first extensive interview about his decision to leave. “But when people start to question the truth — Who won the 2020 election? Was Jan. 6 an insurrection? — I found that unsustainable.”

“I spent a lot of 2021 looking to see if there was a different place for me to do my job,” he added…

He confirmed reports that he was so alarmed by Mr. Carlson’s documentary “Patriot Purge” — which falsely suggested the Jan. 6 Capitol riot was a “false flag” operation intended to demonize conservatives — that he complained directly to Fox News management.

“Before, I found it was an environment in which I could do my job and feel good about my involvement at Fox,” Mr. Wallace said of his time at the network. “And since November of 2020, that just became unsustainable, increasingly unsustainable as time went on.”