<<Mike, does authentic leftism exist in Canada?>>
More as a legacy, primarily our "socialized" medicine, which is the legacy of the late Tommy Douglas, a former socialist Premier of the Province of Saskatchewan. In a recent poll, Tommy Douglas was voted "the greatest Canadian" and IMHO he certainly was that. Joe Salsberg, who passed away a long time ago, was a long-serving Communist member of our Provincial Legislature, and on his death drew eulogies and praise from the leaders of all major parties in Ontario.
To the extent that any kind of leftism exists today, it's in the form of "splinter parties," for example in our last Provincial election, in my own riding, there were candidates from both the Communist and the Marxist-Leninist Parties on the ballot, but their combined share of the vote was minimal.
We never had a Socialist Party as such, we had the CCF (Cooperative Commonwealth Federation,) which became the NDP (New Democratic Party) in an effort to differentiate itself from its more dogmatic socialist roots. In our last Ontario NDP government, the party leadership moved so far to the centre that they really alienated their traditional labour union supporters, particularly in the civil service, where some of the most powerful unions are located. The whole idea of public ownership of the means of production had been abandoned long before the NDP was voted into power here, the most they are willing to go for today is public ownership of some essential industries (say airlines and railways) not even by the government itself but by "Crown corporations" which operate independently of the government of the day almost like private industry.
Bloc Quebecois, like the other separatist and former separatist parties, came out of a Liberal -PC environment, so they are more or less capitalist parties with some socialist leanings. Jacques Parizeau, for example, a former leader of the PQ, was instrumental in the nationalization of the Quebec aluminum and hydroelectric industries, but he did that when he was a member of a traditional party in Quebec, not when he was a separatist. The whole Quebec thing is hard to sort out along traditional socialist-capitalist lines, they're sort of a world unto themselves and besides, even the liberal and conservative parties there have elements that Americans would probably consder socialistic. Besides which, the separatists are bedevilled by nationalism and "racial purity" problems with left and right wings taking different views, some of the more liberals base the whole question more on language than race. It's pretty complex.