This topic is a difficult one. One way to narrow and make it more manageable would be to focus on Clara. Magic realism is more central to Clara's characterization than to that of any other major character in the novel. Her clairvoyance and other-worldliness give her a certain calmness and inability to be controlled that makes her able to maneuver in this patriarchal Chilean society. Her supernatural powers make her a formidable equal to Estaban's bluster.
Clara does participate in political activities. She holds women's meetings at Tres Marias; she befriends those that are beneath her in class; she is democratic (but not capitalistic) in spirit. She may represent the mystical side of Chile--its indomitable spirit that may be subdued by capitalism, land feuds, assassinations, even religion, but whose courage and strength cannot be broken.
Clara dies before the novel is over, but we see Clara's influence in Blanca's rebellious acts as well as Alba's, who aggressively fight tyranny and work to break the cycle of hatred and revenge.