cabecilla

n. hothead, extremely temperamental or violent person; ringleader, leader; sachem

= kingpin, standard-bearer, ringleader, leader of the pack.
Ex: Adam Urbanski is kingpin of a new breed of union leaders who want to be partners, not adversaries, in the school improvement crusade.
Ex: He was a rebel and an anti-establishment standard-bearer of intellectualism and internationalism.
Ex: She admitted to having been the ringleader of the girls who played hooky.
Ex: She has been telling him that he is a beta male, a subordinate figure, and must learn to become an alpha male, or leader of the pack, before the public can accept him as President.
----
* cabecilla de la banda = leader of the pack.