In 1997 Lida Salehi enthusiastically worked on the presidential campaign of Mohammad Khatami, the reformist candidate. She even talked her parents, who had not cast a ballot since the referendum in 1979 that turned Iran into an Islamic Republic, into voting for him. "I believed that he was the man who would bring change, especially because of what he said about freedom and democracy," said Ms. Salehi, a 25-year-old painter. She has voted for reformist politicians in three more elections since then. Now, with parliamentary elections scheduled for February, she and many others who supported the reformists are changing their...