MONTREAL — To understand the counterintuitive political calculus behind Justin Trudeau’s controversial decision to buy the Trans Mountain pipeline, one has to go back to the fundamental equation that has governed this prime minister’s energy and climate change policies since his days in opposition.

That Trudeau had no choice but to take over the pipeline if he wanted to ensure that the plan for its expansion did not die on the drawing board is not in question. By the time Finance Minister Bill Morneau announced the federal decision Tuesday, Kinder Morgan — the pipeline’s parent company — was about to pull the plug on the project.

But the real question is why would the Liberal government be willing to put an open-ended amount of political and financial capital on the line to keep it alive.

If one connects the dots between most major policies that past governments have deemed to be in the national interest, one almost always finds they conveniently intersected with a ruling party’s election prospects.

Stephen Harper’s decision to bail out the auto industry in 2009 was not unrelated to the fact that his path to a coveted majority government ran through Ontario. His conversion to deficit financing at the time of the global economic crisis was a deathbed one, at least in part dictated by the need to survive confidence votes in the House of Commons.

But by that measure, Trudeau’s Trans Mountain move is an outlier. The electoral math does not add up.

On the face of it, the prime minister has at best shored up half a dozen Liberal seats in the Prairies at the cost of potentially putting in play at least triple that number across the country. Along the way, Trudeau has put himself on a collision course with many Indigenous constituencies, and he has destroyed his international reputation as a climate change crusader.

Given the stakes, the prime minister’s pipeline gamble has even been compared to Brian Mulroney’s decision to roll the dice in his relentless quest for constitutional reconciliation with Quebec in the early 1990s.

Bill Morneau laid out Tuesday the federal government’s plan to buy Trans Mountain and Kinder Morgan Canada’s core assets for $4.5 billion. The finance minister says the move will “ensure” the oilsands pipeline expansion gets built. (The Canadian Press)

But Mulroney had a compelling incentive to stick with the constitutional file to the bitter end. After the Meech Lake accord failed, he could not have let it go without risking his governing majority as the result of defections to the nascent Bloc Québécois and without fuelling support for Quebec secession.

There is an economic case to be made for ensuring the Trans Mountain pipeline is completed. Of the projects designed to link the Alberta oilfields to tidewater that were on the drawing board when Trudeau became prime minister, it is the only one that is still actively pursued. Until the last B.C. election, it was also considered the most likely to get to completion.

But the Trans Mountain expansion has also become as politically indispensable to Trudeau’s agenda — at least in the mind of its Liberal overseers — as it may be to Canada’s oil industry.

It was always meant to be the poster project for the federal contention that it is possible to balance Canada’s energy ambitions with a more aggressive approach to mitigating climate change.

Since Trudeau came to power, the emphasis has been the part of the equation that involves putting a price on carbon pollution as a necessary step to earn a social license for a pipeline projects such as Trans Mountain.

But the Liberal government believes the flipside of the equation — that a social license for a carbon tax cannot be sustained if it is earned on the back of Alberta’s energy industry — to be just as essential.

Allowing the Trans Mountain expansion to die this week would have cost Trudeau the support of Alberta’s NDP government for his national climate change framework. Back in March, Premier Rachel Notley tied meeting Ottawa’s carbon tax targets to the future of the project.

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Looking to next year’s federal election, the demise of the Trans Mountain expansion would have meant giving opponents of Trudeau’s carbon pricing strategy — starting with the federal Conservatives — a prime exhibit in their prosecution of the havoc they argue his policy will wreak on the economy.

As so it is that while Trudeau is widely portrayed as having picked the polluters’ side in the climate change debate, the Liberals will argue that they have done what they needed to do to continue to advance a pro-environment agenda.

Only time will tell whether this government has trapped itself in an intricate web of twisted logic. If so, as of this week’s Trans Mountain announcement Trudeau is unlikely to untangle himself from that web in time for next year’s election.

Chantal Hébert is a columnist based in Ottawa covering politics. Follow her on Twitter: @ChantalHbert

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