Yes, Rafsanjani is a crook.
Yes, Moussavi said and did some terrible things, back in the day.
Yes, they were both accomplices of Khomeini, not just in overthrowing the Shah but in setting up the Islamist tyranny.
No, neither of them is going to have a good word to say for Israel (though Moussavi might say something nice about the United States).
Of course that’s all true. And so what?
No one who said and did the sort of things that you and I, dear reader, would approve of could be a political player in today’s Iran.
The survival of an unpopular ruling elite depends on a certain amount of cohesion among its leaders. (And yes, we know the regime to be unpopular. Forget the details of how this election was stolen: the mullahs already knew they couldn’t win free elections, which is why they have the Guardian Council to vet the candidates.)
The members of a tyrannical ruling group may hate and fear one another and plot against one another, but they must all draw the line at actions that threaten the tyranny itself. Rafsanjani and Moussavi have crossed that line, and in doing so they have seriously damaged the credibility of the regime. If they win, they win with the support of all those marchers in the street, who are, on average, much more hostile to clerical rule than are Rafsanjani and Moussavi.
The result won’t be a liberal republic, but it will be much more liberal (about private life) than anything Iran has had since 1979 and much more republican (about political life) than anything Iran has had since the overthrow of Mossadeq. It won’t be friendly to the United States or Israel, but it will be much less bellicose than Khamene’i and Ahmadi-nejad have been, and much less bellicose than they will be now, after using anti-Americanism as their main weapon agaist the insurgency.
In politics, the difference between “bad” and “worse” is all the difference in the world.