They are emboldened by their man, Mir-Hossein Mousavi, who looks like he could actually win, reports CBS News correspondent Elizabeth Palmer.
A 67-year-old architect and painter, Mousavi has promised to liberalize the economy, negotiate with the West over Iran's nuclear program and give young people - especially women - more freedom.
"If Mousavi wins the election, things would change in a better way for Iran," said one girl at a rally.
Mousavi is going into this election knowing he can count on the youth vote. Most of the people who come to his rallies are under 30 - young people who want him to deliver on the freedoms they crave.
But the real star of this campaign is Mousavi's unofficial running mate, his wife, Zahra Rahnavard, who has shattered taboos by sharing the stage with him as an equal, calling to mind another high profile political wife.
"I was active in politics long before people discovered Michelle Obama, a woman I respect," Rahnavard said through a translator.
Her wild popularity has got the competition rattled. During Iran's first ever Presidential debates, Mousavi accused President Ahmadinejad of leading the country to dictatorship.
Ahmadinejad countered by attacking Mousavi's wife, holding up her resume - he said she was an academic cheat, alleging she got a PhD without taking a university entrance exam.
Even if untrue - it went down well with Ahmadinejad's supporters - who think the President can do no wrong. They love his non-negotiable stance on Iran's nuclear program, and pork barrel spending that benefits the working class.
He's a hero in rural towns like Pulur high in the mountains. In the local diner, it's unanimous - everyone's voting for Ahmadinjad for the local improvements he's made.
But for every fan - there's a critic, and Ahmadinejad and his backers are clearly shaken by the ferocity of opposition.
What looks like democracy to some, looks to Iran's Revolutionary Guard like a potential uprising.
A notice appeared last night on the Guard's website, warning that any sign of a popular revolution would be crushed.