David Ignatius relays some interesting analysis:
U.S. intelligence officials tell me that it's quite possible that Ahmadinejad actually did win Friday's election -- though with a lower total than the 63 percent that the regime is claiming. "It would appear that the results are inflated," said one official, reflecting what he said was the preliminary judgment of the intelligence community. But he cautioned: "Our ability to peer into the Iranian election machinery is very limited."
If that turns out to be true, it raises an interesting counterfactual: Would there have been any street protests if the mullahs had played the election straight? It does seem that much of the outrage (and disbelief) among Iranians stems from Ahmadinejad's surprisingly large margin of victory. Maybe Khamenei outsmarted himself on this one.