Who is Jaime Trueba from The House of the Spirits and what is their importance?

Jaime is Nicolas's twin brother. He is described as a quiet boy, who grows into a reflective adult and becomes a doctor. He is very different from Nicolas. Jaime loves his brother's girlfriend, Amanda, and when she turns to Jaime for an abortion, he unhappily agrees. Jaime's socialist views lead him to support the new government, but when he refuses to accept the demands of the revolutionary military leaders, he is tortured and murdered.