This is the 12468th most frequent Korean word.
당원을
"당원을" is the accusative form of "당원," meaning "party member" in English.
당원을 here refers to members of a political party.
그 당의 당원을 모집하기 위해 홍보 활동을 시작했습니다.
Promotional activities have started to recruit members of the party.
당원을 in this sentence signifies the target audience being party members.
당원을 대상으로 한 무료 세미나가 개최되었습니다.
A free seminar targeting party members was held.
당원을 indicates individuals affiliated with the party in general.