psephomancy (n.)

word-forming element of Greek origin meaning "divination by means of," from Old French -mancie, from Late Latin -mantia, from Greek manteia "oracle, divination," from mantis "one who divines, a seer, prophet; one touched by divine madness," from mainesthai "be inspired," which is related to menos "passion, spirit" (from PIE *mnyo-, suffixed form of root *men- (1) "to think," with derivatives referring to qualities and states of mind or thought). Compare mania.