to elect into a body by the votes of the existing members.

to assimilate, take, or win over into a larger or established group

The fledgling Labor party was coopted by the Socialist party.

to appropriate as one's own; preempt

The dissidents have coopted the title of her novel for their slogan.

verb

absorb , accept , admit , adopt , bring in , bring into line , bring into the fold , connaturalize , convert , draw in , elect , embrace , encompass , enfold , homogenize , homologize , include , incorporate , make one’s own , take in , take over