autocastrarse

Literally to castrate oneself, but overwhelmingly used figuratively in political and cultural commentary for a group or institution voluntarily giving up its own power or influence: el partido se autocastró al renunciar a su plataforma original.

• Los críticos dicen que el partido se autocastró al abandonar sus principios. — Critics say the party emasculated itself by abandoning its principles.
• El medio se autocastró aceptando esa censura. — The outlet neutered itself by accepting that censorship.
• Se acusó a la institución de autocastrarse por miedo a la controversia. — The institution was accused of emasculating itself out of fear of controversy.

Reading autocastrarse only in its literal medical sense — in real usage it's almost always a pointed figurative criticism of self-imposed weakness, not literal surgery.