by Nicole Flatow THINK PROGRESS

Secretary of State John Kerry testifies on Capitol Hill on Feb. 24, 2015.

CREDIT: AP

Outrage escalated over the past week over Republicans’ decision to send the Iranian government a letter attempting to sabotage the Iran nuclear deal. The letter drafted by Sen. Tom Cotton (R-AR) and signed by 46 other members of Congress warned that any deal they strike with the United States and other countries may not last past the Obama administration if it is not also approved by Congress.

As the hashtag #47Traitors spread on Twitter, Secretary of State John Kerry said he was in “utter disbelief” when he read the letter, saying during a Senate hearing that it was unprecedented and dangerous in its suggestion to the world that “if you want to have any confidence in your dealings with America, they have to negotiate with 535 members of Congress.” And President Obama said he was “embarrassed” for the senators for suggesting to the United States’ “mortal enemy” that they can’t trust President Obama.

But now, at least a few of the Republicans who signed the letter are admitting regret for their decision to send the message directly to Iranian officials. Sen. Ron Johnson (R-WI) told Bloomberg News Friday that his “only regret” is “who it’s addressed to.” He also told the Associated Press it “probably would have been better just to have it be an open letter addressed to no one.”

Sen. Pat Roberts (R-KS), who also signed the letter, conceded that the letter “could have been addressed to other folks and gotten the message out,” but added that, “I think the message is more important than who we send it to.”

Some of the seven senate Republicans who didn’t sign the letter sharply criticized the move, along with many editorial boards that have supported the senators as candidates and former Republican Gov. George Pataki. Sen. Susan Collins (R-ME) shared the criticism that comments should have been directed at Obama rather than Iranian leader, while the editorial boards called it a “disgraceful decision” and diminishing the “dignity of the Senate.”

The letter comes in ongoing negotiations over a deal to limit Iran’s ability to enrich weapons-grade uranium, reduce its number of operating centrifuges and advanced centrifuges, and lower its low-enriched uranium stockpiles. In addition to criticisms that Republicans’ letter could upend the precarious negotiations and even provoke violence, legal scholars have pointed out that Republicans made a glaring technical error when they told the Iranians that the Senate must ratify treaties.