O’Donnell’s comments reflect a common confusion among fundamentalist Christians who equate witchcraft with Satanism.
Modern witches are often adherents of Wicca, which was recognized by a 1986 Court of Appeals as a legitimate religion. Though Wiccans believe in magic, the form of witchcraft they practice has little or nothing to do with Satan. In fact Wiccans worship a unifying, universal power that is divided into two equal parts, the God and the Goddess. Wiccan witches do not worship nor even recognize the Christian idea of Satan. Most Wiccan rituals center around nature and Earth cycles, such as the solstices. Wicca also incorporates many New Age beliefs, and witches often cast runes, or read tea leaves or Tarot decks to divine the future. Witches also claim to cast spells (of debatable efficacy) for everything from luck to love.
Wiccans hold a wide variety of beliefs, including a version of karma in which whatever you put out into the world — good or ill — comes back to you threefold. Non-Wiccans attending witchcraft rituals would likely find them rather boring — lots of worshiping the sun and moon, dancing, chanting, burning herbs, lighting candles, and so on. People expecting goat or baby sacrifices to Satan are in the wrong place. To be sure, a few self-styled "Satanists" do exist, mostly among disaffected youth. But this is neither an organized movement nor an actual religion.
As for the fear that witches engage in a crusade to lure others into their ways, Sheena Morgan, a High Priestess of Wicca and author of "The Wicca Handbook: A Complete Guide to Witchcraft & Magic," (Vega, 2003) notes that "Wiccans are more than happy to accept that other religions are equally valid and that there are many different routes to the same end. Because of this, Wiccans do not proselytize or try to convert those of other religions."
The fact that O'Donnell "dabbled" in witchcraft as a teen is by itself not particularly scandalous nor newsworthy — except among her ultra-conservative supporters. Some people claim to be vampires; some people claim to be witches, and a handful claim to be Satanists. They can, of course, call themselves whatever they like — maybe even "former witchcraft dabbler Senator O'Donnell."
Benjamin Radford is managing editor of the Skeptical Inquirer science magazine. His new book is Scientific Paranormal Investigation; this and his other books and projects can be found on his website. His Bad Science column appears regularly on LiveScience.