The Murdochs control a media empire which, in the U.S., includes Fox News, Fox Business, the New York Post, and the Wall Street Journal. Fox News has been the primary TV outlet for news that didn't overtly reflect hate of the President.
As such, it has been a favorite with half the populace which likes Trump, and voted for him. As we've noted before, this netted them a very large cable viewership, far outstripping the competition.
This November, for whatever reason, Fox News hired an election analyst who made early calls favoring Democrats. They generally moved closer to other news outlets in the anti-Trump bias of their coverage. Conservatives, feeling betrayed, are mightily upset with Fox as a consequence.
Rupert's son, who heads the network, is either less business savvy or more liberal than his papa - actually both are likely. Giving up Fox's effective monopoly market position was a lousy business decision, soon to be reflected in lower ratings and a consequent drop in what they can charge for ads.
While bad for business, it may improve the younger Murdoch's social position among the glitterati with whom wealthy folks like him tend to hang. He may have enough dough banked to prefer social approbation to fantastic earnings.
From a business point of view, what Fox has done is create an opportunity for another provider to pick up its pro-Trump viewers, as other news aggregators have picked up much of the former readership of the Drudge Report, which made a similar leftward move.
At this point I believe possible contenders OANN and Newsmax are not providing a quality viewing experience. Perhaps they can improve or maybe other providers will come forward.