A few months ago, France's conservatives held a primary to designate their presidential candidate and an outsider, François Fillon, won handily. This week, the left is voting to choose its presidential hopeful and the favourite after the first round, Benoit Hamon, is a man who was not on the radar just a few weeks ago. This means that aside from far-right leader Marine Le Pen, all the favourites to win this spring's elections are out of contention. A most unusual election season is upon us.