Pragmatic Policies

As president between 1989 and 1997, Rafsanjani clashed with Khamenei and hardliners over his pragmatic plans to mend relations with regional states and liberalize Iran's economy.

But it was support for the reformist "Green Movement" protests against Ahmadinejad's disputed 2009 election win that cast him out in the cold.

Last week, Rafsanjani said he would not enter the fray without Khamenei's consent. But analysts say a last-minute agreement with the supreme leader may not have been the ringing endorsement the former president was looking for. "Khamenei can see this as a personal challenge or a means to enhance the legitimacy of the system as a whole," said Farhi.

Khamenei may also be unable to rein in conservatives and the powerful Islamic Revolutionary Guard Corps, which wields both political and economic influence, from going on the attack. Rafsanjani is in some ways an easy target.

"Rafsanjani's wealth and business dealings present a huge vulnerability," said Shaul Bakhash, a politics professor at George Mason University in Virginia.

"Since Khamenei can't really control them, the conservative establishment, its clerical associates and the Revolutionary Guards are certain to mount a massive campaign against him."