As a witch myself I doubt any of the Clinton's are witches. The articles you listed only display them as mildly interested in the subject. Also not all Satanists are witches. Satanists are atheists that just very much try to make themselves opposed to the Christian dogma so they say they praise the least godly thing being satan. I'm not a Satanist but even I understand this basic fact. Though I doubt they are witches, they probably use some form of magick whether it be angel communication or ancestor work.