I wasn't impressed by the evidence of fraud in this morning's reports about the Iranian election. According to the New York Times, Moussavi complained of "shutting down Web sites, newspapers and text messaging services throughout the country, crippling the opposition’s ability to communicate during the voting." That's serious but doens't account for a 40 point defeat. What I would look for are wide disparties between what a candidate received in a place where he is known to be popular and what the current election results claim.  I recommend this post by Juan Cole on "Stealing the Iranian Election."  He has got the first real evidence I've seen. Here is an excerpt:

It is claimed that Ahmadinejad won the city of Tabriz with 57%. His main opponent, Mir Hossein Mousavi, is an Azeri from Azerbaijan province, of which Tabriz is the capital. Mousavi, according to such polls as exist in Iran and widespread anecdotal evidence, did better in cities and is popular in Azerbaijan. Certainly, his rallies there were very well attended. So for an Azeri urban center to go so heavily for Ahmadinejad just makes no sense. In past elections, Azeris voted disproportionately for even minor presidential candidates who hailed from that province..... Ahmadinejad is claimed to have taken Tehran by over 50%. Again, he is not popular in the cities, even, as he claims, in the poor neighborhoods, in part because his policies have produced high inflation and high unemployment...It is claimed that cleric Mehdi Karoubi, the other reformist candidate, received 320,000 votes, and that he did poorly in Iran's western provinces, even losing in Luristan. He is a Lur and is popular in the west, including in Kurdistan. Karoubi received 17 percent of the vote in the first round of presidential elections in 2005.

-- John B. Judis