President Donald Trump’s ravings against the 2015 Paris climate agreement are partly a product of his ignorance and narcissism. Yet they represent something more. They are a reflection of the deep corruption of the US political system, which, according to one recent assessment, is no longer a “full democracy.” American politics has become a game of powerful corporate interests: tax cuts for the rich, deregulation for mega-polluters, and war and global warming for the rest of the world. By Jeffrey D. Sachs.