Since the cult success of Merci Patron!, activist/journalist/filmmaker François Ruffin has become an MP. Here, he attempts to table a law aimed at upholding the rights of what in Quebec are known as caregivers, and shows us in passing how a law whose need seems patently obvious is put together, debated, voted on and . . . dies on the battleground of French politics. A stirring documentary about social injustice that somehow manages to make us bust a gut laughing as we rage with indignation. And also cry at the beauty of it all, thanks to the director’s humanist sensibility and a deft play between reality and fiction.…