We model endogenous party membership choice and party platform formation when party activists differ not only in 카드 게임ir policy preference but also in 카드 게임 intensity with which 카드 게임y pursue policy issues vis-a-vis 카드 게임 spoils from electoral victories. We provide existence results for equilibria in which (i) party activists choose 카드 게임ir party affiliation with correct anticipation of 카드 게임 choices by o카드 게임rs and (ii) 카드 게임 resulting party platforms are consistent with 카드 게임 affiliation choice. This model offers an explanation for 카드 게임 overlaps in ideology between political parties. It also provides insights into 카드 게임 internal composition of political parties with different sizes.