Enrique Peņa Nieto, Justin Trudeau, and Barack Obama were literally all leaders a half-decade ago.
Saying this with the implication that any of these people are remotely left-wing is peak Blairism - specifically, the weird post-2007 becoming-a-cranky-Tory-in-retirement Blairism. When Tony Blair was in power, he was significantly to the left of all three of these. That is something both he and his current supporters, all five of them, seem to have forgotten.
They are all out of the respective political left wings of their own countries; ergo they are left wing.
Incorrect. Trudeau is the leader of Canada's centrist party. Almost a third of Canadians voted for a party to his left. Their policies may be vaguely centre-left (debatable), but they don't represent the left on Canada's political spectrum.
I don't know enough about Mexican politics, but I'm under the impression the same could be said about President Ken Doll.