A Facebook spokeswoman provided a statement from Mr. Bosworth in which he said that the post “wasn’t written for public consumption,” but that he “hoped this post would encourage my co-workers to continue to accept criticism with grace as we accept the responsibility we have overseeing our platform.”

Ultimately, the decision on whether to allow politicians to spread misinformation on Facebook rests with Mr. Zuckerberg. In recent months, he has appeared to stand firm on the decision to keep the existing ad policies in place, saying that he believes Facebook should not become an arbiter of truth. But he has also left himself room to change his mind. In November, a Facebook spokesman said the company was “looking at different ways we might refine our approach to political ads.”

Among those lobbying Mr. Zuckerberg is President Trump himself, who claimed on a radio show on Monday that Mr. Zuckerberg had congratulated him on being “No. 1” on Facebook during a private dinner.

Mr. Bosworth said he believed Facebook was responsible for Mr. Trump’s 2016 election victory, but not because of Russian interference or the Cambridge Analytica scandal, in which millions of Facebook users’ data was leaked to a political strategy firm that worked with the Trump campaign. Mr. Bosworth said the fallout from the Cambridge Analytica revelations — uncovered by The Times, working with The Observer of London and The Guardian — rightly changed the conversation around how Facebook should handle user data, and which companies should be given access to that data.

But, he said, Mr. Trump simply used Facebook’s advertising tools effectively.

“He didn’t get elected because of Russia or misinformation or Cambridge Analytica,” Mr. Bosworth wrote. “He got elected because he ran the single best digital ad campaign I’ve ever seen from any advertiser. Period.”

Mr. Bosworth, a longtime confidant of Mr. Zuckerberg’s who is viewed by some inside Facebook as a proxy for the chief executive, has been an outspoken defender of the company’s positions in the past.

In 2018, BuzzFeed News published a memo Mr. Bosworth wrote in 2016 justifying the company’s growth-at-all-costs ethos, in which he said the company’s mission of connecting people was “de facto good,” even if it resulted in deaths.