First and most obviously, the moderates within the regime, including Rouhani and his close friend and political ally, Foreign Minister Javad Zarif, negotiated the agreement, and are now the most vocal in defending it against Iranian hawks. Rouhani crushed his conservative opponents in the last presidential election in 2013 in part because he advocated for a nuclear deal. This agreement is his Obamacare—his major campaign promise now delivered. Former Presidents Ali Akbar Hashemi Rafsanjani and Mohammad Khatami, as well as moderates in the parliament and elsewhere in government, have also vigorously endorsed the accord. During the negotiations, Rafsanjani, for example, celebrated the fact that Iran’s leaders had “broken a taboo” in talking directly to the United States. Since the agreement was signed, he has said that those within Iran who oppose it are “making a mistake.”

Second and somewhat surprisingly, many prominent opposition leaders also support the deal. Mir-Hossein Mousavi, a popular presidential candidate in 2009 who is now under house arrest for his leadership of the Green Movement protests against Ahmadinejad’s reelection, backed the pursuit of the agreement, albeit with some qualifications. He’s joined by other government critics, some only recently released from Iran’s prisons. Shirin Ebadi, an Iranian human-rights activist and Nobel laureate now living in exile, expressed the hope after an interim agreement was reached in April that “negotiations come to a conclusion, because the sanctions have made the people poorer”; she labeled as “extremists” those who opposed the agreement in Iran and America. Akbar Ganji, an Iranian journalist who spent more than six years in prison in Iran, also praised the agreement, writing that “step-by-step nuclear accords, the lifting of economic sanctions and the improvement of the relations between Iran and Western powers will gradually remove the warlike and securitized environment from Iran.”

Polls show that most Iranians agree with these positions, and public opinion is apparent not just in the Iranian government’s numbers but also in the results of earlier surveys conducted by the University of Maryland and Tehran University. The sentiments of many ordinary Iranians were manifest in the spontaneous demonstrations of joy that took place in many Iranian cities after the agreement was announced.

A new poll also indicates that two-thirds of Iranian Americans favor the agreement, and our own conversations with members of the Iranian diaspora bear this out. The Islamic Republic has long enjoyed some defense from a handful of non-governmental organizations in the West, but support for the nuclear deal stretches much deeper into the diaspora and includes those who despise Tehran’s theocracy. For instance, many prominent Iranian American business leaders have told us they approve of the accord. Iranian American foundations and community-service organizations have issued statements backing the deal, while also calling for renewed focus on political reforms inside Iran. Even many of those who had to flee the country after the 1979 revolution, and have since helped fund projects to encourage democracy inside Iran (including, in the past, our own Iran Democracy Project at Stanford’s Hoover Institution), support it. There are exceptions. Some in the diaspora still believe that only more pressure, and if need be a military attack, will bring down the Islamic Republic. But the number of Iranian Americans who are at once critical of the regime and supportive of the nuclear deal is striking.