I totally disagree with the Western journalists who brand AhmadiNejad as a hard line conservative. He is, with no doubt, a total fundamentalist who is not even shameful of it: They call themselves "Osool gerayan" or literally fundamentalist.
Meanwhile the political climate is rapidly changing in favour of Rafsanjani. All non-fundamentalist groups are rallying behind Rafsanjani, as they see him as the only choice Iran now has to escape a fundamentalist government.
People are also becoming more conscious about this crucial choice, which could be seen as a total referendum on Supreme Leader's vision for the future of Iran. I've personally come across to some young friends who didn't vote in the first round, but are going to vote for Rafsanjani in the second.
So I'm seeing signs of a large voter turnout again, especially in big cities where people are worried about their social, and cultural freedoms, which in turn increases the chance of another Rafsanjani term.
However, if Rafsanjani can't win by a safe margin, as commit ed as Ahmadi Nejad supporters are, it's likely to see some sort of small-scale and legit coup, like the one happened last year during the opening of the Imam Khomeini International Airport in South of Tehran.