The answer to the question as you pose it may be yes, but that brings no legitimacy to IRI. The "legitimacy" card has been way overplayed by the so-called opposition outside Iran, and at a very significant price I may add.
In each of the last few presidential elections more than two third of people participated. Did that convince you that IRI is legitimate? By your argument you must be convinced because majority of people voted and you believe in democracy.
I did not mean to start the whole debate about the legitimicy and ... However, if you insist
then, yes, if you vote , you belive the system as whole, is legitimate. You declare that you agree with the principles that the system is based on however, you disgaree with some of its impelementations and therefore choose to vote to make CHANGES from within the system and based on the constitutions.
I do belive big percentage of Iranian in IRAN do belive in the legitimecy of IR and that is why guys like Khatami has alot of following
So by voting, one opens to door to such a disscutions and contradications. As an another example, look at Mussavi's new speech. He repeats in it ( few times) that we should stay within Iranian constitution and follow it and should ignore it and ....
If that is his message and what he belives, then isn't AN's government constitutionally legetimate ??!! GC counsil approves it, Majles Approved it , Velayat Fagih approved it ....
So this creates contradiction and question. For example, If we accept this constitution:
When did things go wrong ?
Is it just AN and Khamenehi ?
How about few years back ? Was everything during Khatami based on democracy and constitution? and many more questions .......