  The paper deals with a polling game on a graph. Initially, each vertex is
colored white or black. At each round, each vertex is colored by the color
shared by the majority of vertices in its neighborhood. We say that a set of
vertices is a dynamic monopoly if starting the game with the vertices of the
set colored white, the entire system is white after a finite number of rounds.
Peleg asked how small a dynamic monopoly may be as a function of the number of
vertices. We show that the answer is O(1).
