Protests are tearing across France. violence has erupted in its romantic boulevards, looters have invaded the chic boutiques, and the scent of warm croissants and fresh baguettes has been overwhelmed by the whiff of tear gas.For many across Europe, particularly the young, conventional, centrist political parties are failing to revive the continent's stagnating economies. Support for extremist politicians has risen dramatically.We spent a week in Paris trying to understand who and what are driving the demonstrations - and we talked to the leader of France's populist anti-immigration party who now, months away from crucial elections, could benefit from the strife...