Aggressive criticism of the letter by the Democratic party and some of the American public has led some of the original signatories to distance themselves from it subsequently, although the letter also gained an additional signature on Tuesday from Louisiana governor and Republican presidential hopeful Bobby Jindal, who called upon all other potential candidates for the presidency to add their names as well, and make it clear that a harder line on Iran may still be forthcoming in the next few years.

Amidst the controversy Senator Tom Cotton, the freshman legislator at the head of the initial 47 Republicans, took the opportunity to call further attention to the softness of the Iran strategy currently being followed by the Obama administration.

Secretary of State John Kerry testified on Wednesday before a Senate Foreign Relations Committee hearing on the president’s request for authorization for use of military force against ISIL, but also fielded questions regarding Iran. A blog post at Conservative Tree House points out that Kerry explicitly declared in that hearing that the deal currently being negotiated with Iran over its nuclear program is not legally binding.

This led Senator Cotton to ask via a tweet, “If [the] deal with Iran isn’t legally binding, then what’s to keep Iran from breaking said deal and developing a bomb?”

As reported by Iran News Update on Tuesday, Cotton and some of the other signatories, including Florida Senator Marco Rubio have stood fast in defense of their action. And even some of those who did not support the letter have defended the thought process that went into drafting and signing it.

According to Opposing Views, Senator Bob Corker, who serves as the chairperson for the Foreign Relations Committee and declined to attach his name to the letter, said that “a good deal of passion” had clearly arisen in his fellow Republicans in response to the president’s threat to veto what Corker called “a very common-sense piece of legislation” guaranteeing congressional oversight on any deal that is reached between the Obama administration and Iran.

Opposing Views also notes that many of the 47 signatories to the letter regard Obama’s secrecy about the content of those talks with a great deal of anxiety. They are joined by the rest of the Republican Congress and many of the Democratic colleagues in continuing to push the Obama administration to bring the legislative branch into the talks, with the aforementioned legislation serving as the central tool in that effort.

This underscores the Daily Beast’s characterization of the current debate over the letter, which says that “while some on the Republican side are now rethinking the wisdom of sending a letter, none of the 47 Republican signatories are recanting their support for it or signaling an intent to do so.”

Still, the response from the other side has been vociferous, and a petition on the White House website to file charges against the 47 senators for violating the Logan Act by communicating with a foreign government in an effort to influence foreign policy acquired 150,000 votes in approximately 48 hours, surpassing the threshold required for a written response from the administration.

What’s more, criticism has not come only from the political left, and the Daily Beast quotes Republican Senator Jeff Flake as explaining that he declined to sign the letter because doing so injected too much political rhetoric into an issue that is “too important to divide us among party lines.”

Indeed, partisanship has already been seen as interfering with what would otherwise be bipartisan, albeit slower or less urgent action aimed at creating a stronger voice for a Congress that is much more hardline than the Obama administration on the issue of Iran’s nuclear program and the Islamic Republic’s behavior in general.

Last week, following a speech to Congress by Israeli Prime Minister Benjamin Netanyahu, Senate Majority Leader Mitch McConnell moved to fast-track the legislation granting congressional oversight on the nuclear deal, the Iran Nuclear Agreement Review Act. This prompted the leading Democratic co-sponsor of the bill, Robert Menendez, to accuse McConnell of “hijacking” the bill for partisan purposes, and the plan was scrapped in favor of voting on INARA only after the March 24 deadline for a framework agreement between Iran and the P5+1.

Given Congress’s bipartisan skepticism about Iran policy in general, the unilateral action by the 47 Republicans is also being blamed by some commentators for further solidifying the country’s focus on the nuclear issue while distracting from broader issues related to Iran.

CNN points out that members of the Senate Foreign Relations Committee took Wednesday’s hearing as an opportunity to grill Secretary of State Kerry on the Obama administration’s policy of encouraging Iranian military action against ISIL, and thus strengthening the Islamic Republic’s influence in Iraq.

Although apparently buried beneath a wealth of headlines about the Republican letter, Kerry responded to these inquiries by insisting that Iran and the US have common cause in Iraq and are mutually satisfied with cooperative policies there. “They would welcome our bombing of ISIS,” Kerry said, using an alternative acronym for the Islamic State. “They want to us to destroy ISIS. They want to destroy ISIS.”

But these comments stand in contrast to various comments by Iranian officials dismissing the coalition airstrikes as insignificant and suggesting that an Iranian led coalition comprised of its allies in the region would be sufficient to destroy ISIL. Among those allies are the Shiite-dominated government currently presiding in Baghdad, the regime of Bashar al-Assad in Syria, which was once explicitly opposed by the Obama administration, and a number of Shiite militias and paramilitaries operating both within and beyond those territories.