The rise of Thomas Mulcair brings Canada one step closer to a settling of its parliamentary landscape. This former Quebec Liberal, whose one-time boss was a former Progressive Conservative, will henceforth parry with the Liberal interim leader — a former NDPer — and the Conservative Prime Minister, previously of the Canadian Alliance, which not long ago went by the name of the Reform Party.

The preceding highlights the fluid, and in some cases opportunistic, character of recent Canadian politics. Mulcair’s candidacy invoked the familiar weighing of purity against pragmatism, a debate concerning whether one should advance the candidate who can win, rather than the candidate who is authentic. Given that the victor has among his assets deep-pocketed campaign contributors and experience in Quebec and a notoriously combative style, it appears pragmatism has won this time around. Refusing to cut a self-serving deal, Nathan Cullen has won the war of principle by foregoing what the author and politician Nicholas Flood Davin termed, in his 1876 satire The Fair Grit, the “buncombe struggle” — in which contestants “out-vie each other first in professions of purity, and then out-do each other, as far as it is possible, in acts of corruption.” Under Davin’s formulation, “In Opposition all is virtue; in power all the reverse.”

In a slightly modified form this principle, long familiar on the Social-Democrat left, demands of virtue and authenticity the rejection of compromise for the purpose of achieving political power. Considered from the perspective of expedience, however, Mulcair is impressive: a serial first-placer, he is chronologically second only to Phil Edmonston on the list of winning Quebec NDP candidates. (If one puts aside by-elections, Mulcair becomes the first NDP candidate to win a Quebec seat in a general federal election.) Regarding the second criterion, authenticity, there are skeptics and detractors. Judy Rebick asserts that “the NDP has elected an old-style patriarchal politician [who is] more of a liberal than a social democrat and who will move the party to the right, especially on international issues including free trade and Israel, two issues at the centre of Harper’s agenda.” As John Ivison notices, [“Thomas Mulcair’s challenge is to prove he is no political opportunist”] and Rebick discloses, Mulcair must now navigate a sea roughened not only by external challenges, but by internal rivalries and hostilities.

But let’s return to the theme of fluidity. I was in the East Block office of Senator Di Nino, and in the course of our conversation he produced a framed copy of the December 2003 voting card sealing the Progressive Conservative – Canadian Reform Conservative Alliance merger, signed by all involved. The Senator’s recollections made me mindful of how far, and in such short time, the Reform Party came from being an amateurish western grievance club (my wording, not his) to forming the Government of Canada. Along the way, the movement got a makeover — think Preston Manning — and learned to speak in a language comprehensible east of Winnipeg. In other words, another case of purity yielding somewhat to pragmatism, to the inevitable disappointment of some. Imagine where conservatives would be today, if their representation was parceled amongst two or three inter-warring parties.

Observers have been tempted to recommend a similar effort on the left, thereby forging a united opposition to the Conservatives. While there are no indications that a discussion along these lines has occurred, or even will occur, the NDP shall now be forced to divert precious resources into a fight with the Liberals for dominance. Bob Rae’s provincial record, brought fresh to the mind in recent attack ads, arguably makes him appear “more NDP” than the NDP. In any case, you must have noticed how similar is the diction of Mr. Rae to that of the Occupy movement, which is a tactical inconvenience if you are Mr. Mulcair. Should both remain long in leadership, there will hardly be an environmental niche sufficient to nourish them: something must give way. The New Democrats are well positioned to seize the Liberal party’s traditional ideological niche, just as they’ve occupied their traditional seats in Quebec. Mulcair’s chief problem is that the Liberal Party of Canada will soon sort out its internal affairs, and once it has done so it will be back to reclaim its lost territories. The party is too well-monied, too organized, and too much a feature of Canada’s political establishment to be kept down for long. In the short time he has, the NDP leader must apply his attention, not to defeating Harper, but to the long-term goal of holding recent and tenuous gains which the Grits are certain to contest.

If this turns out to be a draining and inconclusive battle, the topic of merger will arise. The ideologically pure will of course have none of it; nonetheless, there are reasons to suspect the years ahead will not be kind to these two parties. In his article, “A budget, a leadership race — and a nation split up the middle,” Andrew Coyne identifies the natural resource industry, demographics, and Quebec separatism as the three “fault lines” of current Canadian politics. Each of these three will doubtless present itself politically as a zero-sum prospect, posing winners against losers and fracturing the country more deeply along regional lines.

To get at the spoils, the parties have positioned themselves accordingly. An intriguing insight of Coyne’s piece is the unpredictable ways in which the politics of regionalism may intersect with the politics of resource extraction and demographics and fiscal federalism. As the loyal opposition, the NDP has an opportunity and a responsibility to take bold stands on these issues. Yet if Coyne is correct, the deepest fault lines are going to run straight through the NDP (and until recently, Liberal) territories. Quebec, for instance, has proven itself to be an especially fickle fair-weather friend. Looking ahead through Coyne’s lens, the political landscape is as fluid as it appears in the backward glance at the beginning of this essay. A sort of political climate change is underway. Interesting times are ahead, and one has to wonder if either the New Democrats or the Liberals are preparing.