cooptar

To co-opt — either to appoint someone to a group without a formal election ("cooptar a un nuevo miembro"), or, in its more critical modern sense, to absorb and neutralize an idea or movement by adopting it ("el movimiento fue cooptado por el partido").

• La junta decidió cooptar a dos nuevos miembros. — The board decided to co-opt two new members.
• Critican que el gobierno haya cooptado el discurso ecologista. — They criticize that the government has co-opted the environmentalist message.
• El partido intentó cooptar a los líderes del movimiento. — The party tried to co-opt the movement's leaders.

Often used in a critical political sense in modern Spanish (absorbing and defusing a movement or idea) rather than the neutral original sense of simply appointing someone — context usually makes clear which is meant.