Trudeau won because Quebec gave him 40 seats. Quebecers typically vote for a Quebecer & vote as a block to determine Canadian federal elections. The Bloc was a brief anomaly. It didn't work so they went back to the tried and true formula.  Justin is seen as a Quebecer (technically speaking was born in Ottawa) trades on his father's popularity, is married to a Quebecer, has a French surname and of course speaks French.  Most English Canadians are clueless that Quebecers are typically your Prime Minister & Quebec absolutely determines who wins!