As the controversy escalated on Tuesday, talks on Iran's nuclear program continued, as did efforts to ensure that Congress can approve or veto an agreement, if one is reached. Those organizing the letter netted an additional supporter -- a leading Democrat at that. Corker said Sen. Michael Bennet (D-Colo.) now backed his efforts.
Sen. John McCain (R-Ariz.), who supports Corker as well, said he was confident there would be enough Democratic votes to bypass a presidential veto and secure a congressional say on an agreement with Iran. That, he added, was adding to the frustrations of the White House over Cotton's letter to Iran.
“What this is all about is that they know that this deal, from what we know about it, the number of centrifuges and the 10-year expiration date, that they would have one heck of a time getting it through the Congress of the United States, including a lot of Democrat votes," McCain told HuffPost. "This is why there’s the hysterical reaction.”