We know from Cardinal Danneels, a key member of Pope Francis' Council of Nine, that he was part of this radical "mafia" reformist group opposed to Benedict XVI
The late Jesuit Cardinal Carlo Martini was a great enemy of the Catholic Church who many feared would overtake the Papal Throne as an anti-pope had Pope John Paul II met with an untimely death. Martini is well remembered for the way he attacked John Paul II in the press and called for his resignation because he didn't support a woman's "right" to have an abortion.
For obvious reasons Martini likewise despised Cardinal Ratzinger [now Benedict XVI], though he was very good friends with the Jesuit cardinal Jorge Bergoglio [now Pope Francis], and fearing that Ratzinger might become the next pope Martini set up "St Gallen Mafia" in an attempt to prevent Ratzinger from being elected pope and to try to get Bergoglio elected instead.