What was Mayor Bloomberg thinking? That’s the question being asked by those who nurse classical newspaper values. The idea that Hizzoner could pull his vast journalistic enterprise — and it is vast — out of the political fray was naive enough. But to try to do it by halting investigations of the Democrats while continuing them of the Republican incumbent is just . . .

Forgive us. There’s no charitable way to put it. He was thinking with, as his mother (and ours) would have said, his tuchus. The Wall Street Journal was the first to mark — cheerfully and in a good spirit — how absurd was Mr. Bloomberg’s reasoning. It’s editorial, “Bloomberg No News,” lampooned its competitor for calling his reporters off his fellow Democrats while siccing them on Mr. Trump.

“If Bloomberg can’t pledge to cover both parties equally,” the Journal concluded, “it would be better not to cover the election at all.”

Meantime the ex-mayor of the city that passes for the capital of the news industry decided to close-down altogether the editorials through which the Bloomberg empire expresses its owner’s views. The Sun lurks well to the right of those views. We don’t mind confessing, though, that we had became a faithful reader of Bloomberg’s editorials. They were the best thing on the whole Bloomberg report.

Plus, too, what better way than through such editorials could there be for a candidate to offer in a presidential campaign a stream of his views on the issues of the day? Instead, the editorials have gone by the boards and their writers have been hived off to the presidential campaign. That strikes us as counterproductive from everyone’s point of view, including that of his customers.

Back in the days when newspapers were expanding, no editor worth his salt would have lost a moment’s sleep over any of this. He’d have his whole galley chronicling the proprietor’s sagacity, rectitude, valor, and vision. At the same time, he would have been publishing scoop after scoop about the nefariousness of his opponents — whoever they might be — and their penchant for communism, graft, and extra-marital affairs.

In any event, it was to be expected that Mr. Trump would come out of his chair. That happened Monday. “Bloomberg News has declared that they won’t investigate their boss or his Democrat competitors, many of whom are current holders of high office, but will continue critical reporting on President Trump,” Mr. Trump’s campaign manager, Brad Parscale, said. He reckoned that is “troubling and wrong.”

So the Trump campaign said it might not accredit Mr. Bloomberg’s reporters to cover Trump campaign events. Mr. Bloomberg’s famed editor, John Micklethwait, retorted that the “accusation of bias couldn’t be further from the truth.” Added he: “We have covered Donald Trump fairly and in an unbiased way since he became a candidate in 2015 and will continue to do so despite the restrictions imposed by the Trump campaign.”

That only raises the question of why, if Bloomberg News can manage to cover Mr. Trump fairly, has it called off its investigative journalists from the Democratic field in the first place. It doesn’t make sense to us. Except as another indication of the enfeebled press, wringing its hands in an era when the government is being floated on irredeemable electronic paper ticket currency, while it runs up its debts to its Chinese communist rival, and journalistic ethics has become an oxymoron.