 Election day is a time of great joy and excitement for us Iranians, the Ayatollah said. The longevity, stability, reputation and honour of the Islamic Republic depends on the people's participation. So the call is for a high turnout, but how much difference can voters actually make? Sanam Vakil is director of the Middle East and North Africa programme at the Chatham House think tank here in London. She's also lecturer at Johns Hopkins University.