adjective

Showing or feeling no interest, enthusiasm, or concern.

apathetic slackers who don’t vote

uninterested,indifferent,unconcerned,unmoved,unresponsive,impassive,passive,detached,uninvolved,disinterested,unfeeling,unemotional,emotionless,dispassionate,lukewarm,cool,uncaring,half-hearted,lackadaisical,non-committal