French farmers have been manning the barricades this week. Dairy prices have gone through the floor worldwide these past months, and French farmers are dumping Belgian milk and Spanish vegetables. And beware politicians: polls suggest a summer surge for several ageing gentlemen with high ambitions. In the United States, real estate mogul Donald Trump is leading in the polls in many states. The youngest of the summer surgers is the UK's 66-year-old Jeremy Corbyn.