It may mean relating to Sanchez or Sancho. In Spain he can be a follower of the current Head of Government, Pedro Spanchez. In Germany he can be a follower of the English player of Borussia Jadon Malik Sancho.
SANCHISTA in Spain : belonging to the doctrine of Pedro Sánchez, President of the Government of Spain. 2 . Person in favor of Pedro Sánchez.