AP Photo

Tehran's main squares and streets have been crowded until the wee hours over this past week, as supporters of the upcoming election's two leading contestants roam the streets on foot and in cars, chanting, honking their horns, waving posters. On Tuesday night, a group of about 100 young men gathered on one side of Parkway Square, waving pictures of President Mahmoud Ahmadinejad and shouting slogans like, "Ahmadi, you're my life! You're my future president!" Facing them — separated by a line of police and plainclothes security officials — stood a crowd of young men at least twice the size. Dressed in green to express support for the moderate challenger Mir-Hossein Moussavi, they chanted back, "Death to this government that lies to its own people!"...