While Harry Potter wards off calamity with a flick of his wand, hundreds of students nationwide are casting more than the occasional love spell, as they identify Wicca and other pagan practices as their official religion. Members of Syracuse University's Pagan Society lighted candles in the campus chapel, while curious students signed up for a new class on witchcraft. And at the University of Arizona and Lehigh University in Pennsylvania, believers can be excused from class on Wiccan holidays. Anthony Paige, a recent SUNY Purchase College graduate who started a pagan student group there, said Wicca appeals to some college...