Hands down, this is the boldest political headline of the year: under the subhead “GOPers try to sabotage Bam nuke deal” and photos of senators Mitch McConnell, Ted Cruz, Rand Paul and Tom Cotton, the New York Daily News yesterday stamped the word “TRAITORS.”

The headline is almost as bold for the mainstream media as the open letter that forty-seven Republican senators sent to Iran’s leaders, offering to explain (inaccurately, as it turns out) how under our Constitution any nuclear treaty they sign with President Obama could vanish once he leaves office. “The next president could revoke such an executive agreement with the stroke of a pen,” they wrote, “and future Congresses could modify the terms of the agreement at any time.”

The misleading missive comes as the United States is in extremely delicate negotiations that could lift sanctions on Iran in exchange for it halting its nuclear program for at least ten years. The politically middle-of-the-road Daily News abhors the deal, but it has an almost old-fashioned sense of propriety, saying in an editorial:

Regardless of President Obama’s fecklessness in negotiating a nuclear deal with Iran, 47 Republican U.S. senators engaged in treachery by sending a letter to the mullahs aimed at cutting the legs out from under America’s commander-in-chief.

The News calls the letter a “petulant, condescending stunt,” and its signatories, which include all but seven GOP senators, “an embarrassment to the Senate and to the nation.”

“TRAITORS” isn’t clever, like today’s New York Post line on Hillary Clinton, “DELETER OF THE FREE WORLD,” and it may not become iconic, like the Daily News’s own “FORD TO CITY: DROP DEAD.” But it packs into one fist of a word what much of the rest of the media have been thinking but didn’t dare say ever since House Speaker John Boehner went around Obama and invited Bibi Netanyahu to warmonger before a joint session of Congress last week.

“TRAITORS” has also provoked, and the News is promoting, a huge Twitter reaction, where #47traitors was one of Tuesday’s top trending hash-tags.

For his part, Obama reacted coolly, saying, “It’s somewhat ironic to see some members of Congress wanting to make common cause with the hard-liners in Iran.” He left the outrage to Joe Biden, who said, “I cannot recall another instance in which senators wrote directly to advise another country—much less a longtime foreign adversary—that the president does not have the constitutional authority to reach a meaningful understanding with them.”

The goal of both the GOP and Netanyahu is to destroy any chance of negotiating with Iran, the better to one day bomb, bomb, bomb it. For the crazy right, which now officially includes the majority of GOP senators, the letter is of a piece with their attempts to repeal voting rights, the Affordable Care Act, science, the Obama presidency and reality itself. (Andy Borowitz cracked the natural joke: “Iran Offers to Mediate Talks Between Republicans and Obama.”)

To top it off, even as the signers condescend to lecture Iran on our Constitution, they get it wrong, as the Washington Post points out, and Iranian Foreign Minister Javad Zarif gets it right, calling the letter “a propaganda ploy” with “no legal value.” From NPR:

Zarif said he was astonished by the letter, saying it suggests the U.S. lawmakers “not only do not understand international law”—a subject in which he is a professor—“but are not fully cognizant of the nuances of their own Constitution when it comes to presidential powers in the conduct of foreign policy,” according to Iran’s Foreign Ministry.

He added, “I wish to enlighten the authors that if the next administration revokes any agreement with the stroke of a pen, as they boast, it will have simply committed a blatant violation of international law.”

Almost as intriguing as the machinations involved in the nuclear deal, and those within the GOP (three signers—Paul, Marco Rubio and Lindsey Graham—are presidential hopefuls) are those at the Daily News that may have led to “TRAITORS.”

The tabloid is owned by billionaire real-estate and media mogul Mort Zuckerman, a staunch supporter of Israel, but not on the Sheldon Adelson scale. The News, which endorsed Obama in 2008, Romney in 2012 and de Blasio the next year, plays it down the middle and several notches more intelligently than its arch rival, the New York Post, owned, as is Fox News, by Rupert Murdoch. Who decided to call sitting senators “traitors”? What was Zuckerman’s input? Was it some kind of last hurrah before the Daily News is sold—possibly to Murdoch?

Just two weeks ago, Zuckerman “shocked” his staff by announcing that he might unload the paper, which he’s owned since 1993. Besides Murdoch, other potential buyers include Mike Bloomberg, “the Dolan family—of Cablevision, Madison Square Garden, and Newsday fame—and the newspaper chain-owning Newhouse clan,” Lloyd Grove writes in the Daily Beast. In the eroding newspaper industry, both NYC tabs are reportedly losing millions of dollars each year—the Post, $70 million, to the News’s $20 million. Grove transmits one of the best lines on the state of newspapering: “New York’s tabloid war, said a battle-scarred veteran, has become a pitiable spectacle of ‘two bald guys fighting over a comb.’”

But that comb has value to Murdoch: if he were to buy and then shut down his rival, he could gain circulation and ad revenue. And most important to Murdoch, he could increase his already enormous political influence in the city as well as the country.

So one day, Murdoch may disappear yet another media outlet, one of the very few in the mainstream willing to call out the Fox News Congress.