He's a socialist. And I didn't mean he's a Dem, he's what's known as a social democrat, it's a form of socialism, socialism-lite if you will, designed as a compromise to try and soften the inherent evils of capitalism.
Social Democrats believe in a capitalist framework with govt regulations, high taxation for the wealthy to pay for social programmes that help to temper the flaws the of capitalism. They believe in the role of government is to represent the working and middle classes and improve life for them and restrain big business, improve working conditions, raise wages, make life better. They generally believe in some nationalised services and some privatised ones.
Social democracy is the only form of capitalism that represents the majority of society's needs.