Bernie Sanders's rise in the Democratic primaries has echoes of Donald Trump’s road to the Republican nomination. He has already changed the tone of the race; can he win it? We take a look at the shadowy history of spies running front companies. And a look back on the life of “Mad Mike” Hoare, an accountant-turned-mercenary. For full access to print, digital and audio editions of The Economist, subscribe here www.economist.com/radiooffer