There is plenty of work to do, but big business isn't investing in rebuilding a green economy for the 21st century. Instead, they put their money into a gigantic financial casino, and when that led to catastrophe in 2008-9, they made us pay for it.

Socialism is a fundamentally different social system where the world's resources are not controlled by a greedy, undemocratic oligarchy. This is not the same as the capitalist welfare states that have existed in some European countries.

The programs that came to be known as the New Deal were not simply handed down by the benevolence of FDR and the Democrats. They were fought for. And in the 1960s, it was the similar. You had incredible movements against Jim Crow, poverty and the Vietnam War in the 1960s.

Bernie Sanders has shown that socialism is no longer the barrier that it used to be during the Cold War.

There are limits to reforming a system that is dominated by these massive and rapacious corporations.

Whether or not you agree with Bernie Sanders' version of socialism, it is enormously significant that, for the first time in US history, a presidential candidates who calls himself a socialist has had an actual shot at winning the presidential election. And to his credit, he has not backed down from the label.

Capitalism is based on ruthless exploitation and competition, and leads inevitably to the development of mega monopolies.