At 5:55 p.m. on Thursday, James Murdoch sent an email to a list of blind-copied recipients offering a striking repudiation of President Trump and a pledge to donate $1 million to the Anti-Defamation League. He addressed the note to “friends,” stating in the first line that he was writing it in a “personal capacity, as a concerned citizen and a father.”

Yet for the son of the conservative media mogul Rupert Murdoch, who speaks regularly with Mr. Trump, it’s impossible to separate the personal, the political and the corporate.

James Murdoch’s message, which he wrote himself, was sent to a number of business associates from his company email address at 21st Century Fox, the global media conglomerate where he reigns as chief executive. And within two hours, it had been leaked to the news media, offering a window into the nuanced internal and external politics of the Murdoch media empire.

The email also raises questions about whether it is a harbinger of change at the Murdoch-controlled conservative-leaning media outlets — including Fox News, The Wall Street Journal and The New York Post — and the political direction of the company under a new generation of Murdoch leaders, James and his brother, Lachlan, the company’s executive chairman.