If Khatami resigns it will be civil war, perhaps it is time for that.
It wont be a civil war, it will be a real revolution.
What happened in 1979 was a coup not a revolution.
If Khatami resigns, which I doubt, The people will find their last way to reform or revolution.
Khatami is not an obstacle, Khatami is a fake moderator of the regime.
If he goes, the whole regime will go faster.
http://www.sumka.org/islamic_paradise_e.htm