An interesting take from Foreign Affairs, in which an Iranian scholar theorizes that an Ahmadinejad loss might, counter-intuitively, be worse for the U.S. in the long run:

…the outcome of the presidential election in June will have some, although probably limited, ramifications for Iran’s foreign policy. President Mahmoud Ahmadinejad and his two major reformist rivals, Mir Hossein Mousavi and Mehdi Karroubi, have all supported engaging in negotiations with Washington — a political taboo just a few years ago.

Ahmadinejad would be less likely to compromise than his more moderate competitors, but, thanks to the support he has among major anti-American constituencies inside and outside the Iranian government, he would be in a better position to institutionalize any shift in policy.

Although Iran’s president can change tactical aspects of the country’s foreign policy, he cannot single-handedly alter its essence. Only Khamenei, the ultimate decider, can do that. And he will do that only if a fundamental change in policy would not undermine his own authority and if it enjoys broad support from among the major centers of power.