Four years ago, during a similarly sultry Tehran summer, I had an argument with Shirin Ebadi about whether Iranians should vote in their country’s presidential elections.

The human-rights lawyer and Nobel Peace Prize laureate believed that Iranians should boycott the vote. She argued coolly that people’s participation lent legitimacy to an undemocratic regime’s flawed electoral process.

At the time, I found her view frustratingly staid, the stance of someone who had lost touch with young people’s immediate concerns. I felt that boycotting elections made a prize of abstract ideals over daily realities.

I had experienced Iran in both the repressive late 1990s and the relatively more open years of reformist president Mohammad Khatami, and not choosing a more open government — however imperfect the process of choice — seemed inconceivable to me.

That summer of 2005, many Iranians actually heeded Ebadi’s call and boycotted the vote. This helped the election of Mahmoud Ahmadinejad, the firebrand leader who proceeded to gut the country’s economy and sully Iran’s reputation in the world.

Reformist politicians, whose candidates had fared badly at the polls, told moderate Iranians that they were to blame for Ahmadinejad’s victory.

If the so called "silent majority” — the millions of middle-class, educated Iranians who seek more freedom and economic opportunity — had voted, the emerging wisdom went, then the country wouldn’t have been lost to the lunatic with the peculiar windbreaker.

In the four years that followed, many Iranians bitterly regretted their decision not to vote. I was living in Beirut in 2005, and failed to cast my ballot at the Iranian embassy there.

When I moved to Iran later that year and began to suffer the slowly emerging consequences of Ahmadinejad’s victory, I scolded myself daily. Ambivalence and laziness had gotten the better of me, and I deserved to suffer the consequences.

I also scolded all my friends and relatives who hadn’t voted. When they complained about double-digit inflation, a real estate price hike of 150%, five-hour lines for gas (the government had botched a plan to drop gas subsidies), Internet censorship, government plans to facilitate polygamy and gender segregation in classrooms, I told them they were to blame, not Islamic theocracy.

They had chosen not to elect a better leader. Even as recently as six months ago, many in Iran were ambivalent about voting in this election.

"Why should I bother to vote when my vote isn’t respected?” a shopkeeper in eastern Tehran said to me. His wife, he said, was already hectoring him to vote.

"She thinks it will make a difference. She’ll probably make me in the end.”

Given the inertia and skepticism that reigned just a few months ago, the sudden energizing of public sentiment in the three weeks preceding the election was extraordinary.

Seemingly overnight, Iranians sloughed their cynicism, and began to follow the campaign avidly. Whatever you attributed this to — a delayed realization of what was at stake, the contagious energy of a youthful campaign that began taking to the streets — the sense of responsibility Iranians began to feel for the election’s outcome was tremendous and unprecedented.

Relatives and friends that I never expected to vote decided to participate. From Tabriz to Tehran to Mashhad, from Bonn to London to Virginia, they waited in long lines at polling stations, determined not to let the country slide further into penury and isolation, not to let 2005 repeat itself.

I was thrilled when some friends e-mailed to say I had helped encourage them to vote. I recently published a memoir of life in Iran under Ahmadinejad, invoking in detail how destructive it was to boycott elections.

I wrote about the day I was led off to a police van, my baby in tow, because a teenage policewoman considered my sleeves too short. This sort of experience spurred my own desire to vote, to try to change the grim, Talibanesque country Iran had become under Ahmadinejad.

Though people outside Iran tend to believe that the country’s elections are always rigged, the truth, at least until recently, was that the regime manipulated results by only a fraction of percentage points.

I never imagined that the election could be hijacked entirely, that fraud could be committed on such an enormous scale. In the decade that I’ve covered Iran as a journalist, it seemed the regime still cared too much about its legitimacy to tamper dramatically with the people’s will.

The constitution, after all, enshrines the will of the people as the basis for sovereignty, and the pretense of democracy has characterized Iran’s revolution as much as political Islam. I spent nearly three weeks in Iran over the winter, talking to clerics, students, street laborers and professionals.

People’s anger and despair over Ahmadinejad’s mismanagement of the economy pulsed throughout Tehran. People were not just discontent, they were punching-the-wall furious.

Dismissing opposition to Ahmadinejad as a north Tehran phenomenon, limited only to affluent urban areas, is insulting to the millions of middle-class Iranians who have suffered the most under his tenure.

As a rule, affluent Iranians aren’t much affected by high inflation and unemployment. As the foreclosure crisis in the United States has shown, it is people of modest or low income who feel the pinch when an economy falters.

I started sniffing around the question of the President’s much-discussed popularity in smaller cities and rural areas. Family and friends whom I trusted, people who spent time regularly outside Tehran, said rural Iranians weren’t as pleased with Ahmadinejad as was supposed.

For every hospital he had built, there was a promise either undelivered, or delivered so shoddily that the project at hand, a bridge or a road, was unusable. I applied for official permission to report a story on the President’s popularity outside Tehran, and was turned down.

Given the government’s constant griping about the Western media only assessing Ahmadinejad through urban attitudes, this seemed suspect.

Despite this, I never for a moment imagined the regime would fix the vote. Others were less sanguine. The thousands of Iranians who were following the run-up to the vote on Facebook fretted about whether the vote would be clean.

Each day brought with it a panicked spread of messages about anticipated vote-tampering: take your own pen to the ballot box, Ahmadinejad’s supporters are spreading pens whose ink will evaporate after a few hours; don’t listen to anyone who tells you that Mousavi supporters are supposed to vote at schools, it’s a plot to tamper with his votes.

The notion that Ahmadinejad won this election by a landslide is farcical. And the tepid response of Western governments, who are clearly most concerned with nuclear negotiations under another Ahmadinejad government, has been shameful.

If it hadn’t been for the extraordinarily high turnout in Friday’s election, the fraudulent result would not have been such a watershed moment for Iran.

That Iranians buried their cynicism and turned out in such record numbers to vote is what makes this such a bleak and precarious moment for the nation. Any vestige of legitimacy that the government might have had in many Iranians’ eyes is now irrevocably lost.

Iran is now on par with nations like Egypt and Syria, where leaders are elected by 99% of the vote in sham elections that bear no pretense to democracy.

I am not ashamed of having voted in Iranian elections past, but I have a fresh appreciation for the wisdom of Shirin Ebadi, who from long experience battling the Iranian regime had accurately recognized her foe.

And I am still not certain that I will boycott elections in the future. If people had not voted in Iran on such a grand scale, the world would have assumed once again that people had chosen Ahmadinejad as their President.

Now Iranians have made their discontent clear, and though their votes have been discounted, their voices have been heard.

Ahmadinejad may remain President of Iran, but his legitimacy has been shaken to its core, not just before his nation but before the world. Iranians managed that by voting, and it is a powerful accomplishment indeed.

TIME