A record 21.6m votes were cast in the election

So the president re-elect can now go back to the hardliners emboldened by the knowledge that every ballot cast for him was a positive show of support, rather than a negative vote against someone else.

He will feel this as a source both of strength, and of obligation to serve the trust that has been placed in him.

"The people of Iran now expect the system and the government to take bigger steps to realise and consecrate their just demands and firm resolve," he said in a message to the nation after the results came out.

Mr Khatami will also be aware of the silent voice of those who refrained from voting.

His victory was impressive, but it was not an overwhelming national vote of confidence.

Vote for change

The turnout was actually more than a million less than 1997, although the electorate has swollen by 5m.

Altogether one-third of the potential voters - 14m people - stayed away, clearly signalling their despair with the system as a whole.

Ahmad Tavakkoli took the bulk of the right-wing vote

Add those abstentions to the half-million people who returned spoiled ballots, plus the 51% of the overall electorate who did turn out and voted for Khatami, and the inescapable conclusion is that 85% of Iranians above the voting age of 15 want change, either radical or gradual.

His supporters hope this clear message from the electorate will get through to the hardliners.

Through their control of such unelected bodies as the judiciary and the Council of Guardians (which among other things vets legislation), they have blocked and set back the reform process in every way they could.

Nobody expects the doors of change to fly open automatically because of this election.

Right-wing backlash?

But by reinforcing the trend of all other elections since Mr Khatami's stunning victory in 1997, it will generally strengthen his hand in his dealings with the recalcitrant right-wingers, whose support is clearly reduced to a maximum of 15% of the public.

The immediate effect will be to increase the pressure on the right-wing camp (which is by no means monolithic), with democratic elements in it feeling the need to get more in tune with the will of the people.

This will further isolate the even smaller minority of hardcore right-wingers who believe fundamentally that power and authority do not come from the people but from God, and that any means is justified to support and enforce that rule.

In the short term, there may be an angry backlash from the hardliners. Their first reaction came on the streets of Tehran when groups of furious Ansar Hezbollah (right-wing vigilantes) attacked and beat up jubilant Khatami supporters celebrating his victory on Saturday night.

Mr Khatami is not a man of confrontation and victory, but of quiet persuasion and unity.

In the coming months and years, he and his supporters will continue pressing their case on all fronts and suffering setbacks on many, but knowing that all the time out in society, the tide of history is moving inexorably in.