The leadership of Iran has been run by anti-American clerics since the days of Jimmy Carter.

The clerics, or "Council of Guardians," get to approve each and every presidential candidate. No one can run without their seal of approval. Do you really think anyone who might shake their grip on the country is going to get approved?

As such, a few more "diplomatic visits" wasn't going to break that stranglehold on the country, regardless of what Bush did or didn't do with Iraq.

Furthermore Iran has been on Russia's 'good side' for approximately the same amount of time. That wasn't something that started with Bush.

Finally, you must not understand what "diplomatic visits" are, if you think they are targeted at the voting public of any country. Diplomats work with the leaders of the government of that country. They don't work with the population to overthrow that leadership. In fact, that sort of "diplomacy" is usually considered "fostering insurrection" and could get our diplomats killed.