DES MOINES — Move over, Donald Trump. Stand aside, Fox News. There's a new feud underway between a presidential candidate and a news media organization — this one between a Democratic presidential candidate, Sen. Bernie Sanders, and the editorial page of this newspaper.

The first volley was the editorial, posted late Wednesday online and in Thursday's print edition, headlined: "A campaign full of fiction." The print edition sub-headline contended, "Sen. Sanders is not a brave truth-teller. He's just telling progressives what they want to hear."

It got even rougher from there. The senator from Vermont is making "fantastical claims about how he would make the European social model work in the United States," ignoring the fact that Wall Street reforms since the financial collapse are "significantly reducing the risks big banks pose," and distorting the fiscal implications of his proposals, the editorial argued.

At a breakfast with reporters here Thursday that was hosted by Bloomberg Politics, Sanders fired back — again and again and again.

"That's not a new argument. We've been hearing that months and months, and that's in a sense what this campaign is about," Sanders said in response to a request for his reaction to the editorial. "People are telling us, whether it's the Washington Post editorial board or anybody else, our ideas are too ambitious — can't happen. Too bold — really? Well, here's something which is really bold. In the last 30 years, there has been a massive transfer of wealth from the middle class and working families of this country. The middle class has become poorer and trillions of dollars have been transferred to the top one-tenth of 1 percent."

Bernie Sanders regularly calls for a "political revolution" in America, but what does that mean? (Peter Stevenson/The Washington Post)

"That's pretty radical, isn't it?" Sanders said. "Where was The Washington Post to express concern that the middle class was shrinking?"

Sanders was just warming up. "Where was The Washington Post talking about this radical transformation of America?" he demanded, then proceeding to go on for nearly four minutes in his rebuttal.

He wasn't finished. Through the remainder of the hour-long breakfast, Sanders found a number of other opportunities to take a swipe about his new foil.

When he was asked about foreign policy, Sanders detoured: "Getting back to The Washington Post — check out where all the geniuses on the editorial page were with regard to the invasion of Iraq." (They supported it.)

At another point: "I know The Washington Post may think I'm radical, but I'm not."

(Note: The Washington Post editorial board operates independently from the newsroom.)

The Post was not his only media target, however. At one point, he was asked a question by New York Times reporter Jason Horowitz, who with Yamiche Alcindor had written a story saying that Sanders's campaign was holding a strategy session to consider whether to go more negative against Democratic front-runner Hillary Clinton.

"Never happened," Sanders told Horowitz. "Not quite sure who you talked to, but next time, talk to me."