Right now, members of both the Liberal Party of Canada and the NDP must feel like they’re watching a bad horror movie. Like most cheap horror flicks, theirs is one in which the protagonist is headed towards some sort of disaster that could obviously and easily be averted, if not for their staggering lack of common sense. It’s the kind that makes you want to shout at the screen out of frustration and say something like “no, you idiot, don’t go into that abandoned shed alone without a flashlight.”

That abandoned shed, for Canadians who are fond of either the Liberals or the New Democrats, is another election in which the two parties remain as distinct and independent entities. The idea of a merger, which would have been unfathomable when Paul Martin took over as leader of the Liberal Party in 2003, has gained a great deal of currency in recent months with the near-collapse of his party and the rise of the NDP. And while it’s often said that politics makes for strange bedfellows, there would be nothing strange about the NDP and Liberal Party deciding to shack up. If anything, it makes perfect sense.

Yes, there are disagreements on policy between the two parties. And yes, there are some old animosities that would have to be overcome. But as backroom strategists in both the NDP and the Liberals already understand, they’re in roughly the same place that the remnants of the Progressive Conservative Party and upstart Reform Party found themselves in almost 20 years ago: lost in the political wilderness, and with no real idea of how to find their way back to civilization.

As they learned in three successive elections, the mathematical realities of two parties vying for one side of the political spectrum in a first-past-the-post electoral system are very unforgiving. The Liberals and NDP now find themselves in exactly that situation. If anything, the road to forming government is even more treacherous for them than it was for Joe Clark’s PC rump or Stockwell Day’s Canadian Alliance. After all, the Conservatives are the uncontested masters of the only side of the political spectrum that’s poised to see organic growth for the next two or three decades, as the aging of the Canadian population will tilt the fulcrum point of Canadian politics ever more in their favour.

It’s not as easy as adding together the vote totals of the NDP and the Liberals in the last election, of course. There would be turnover – and turmoil – in the membership of a new party, one that might be called, say, the Liberal Democrats. On the left, the new party might lose some votes to the Green Party, while on the right it would lose some to the Conservatives. But this is like group of shipwreck survivors quibbling about the condition of the rescue boat that’s come to pluck them out of the water. In the end, it’s their only hope of forming a government in the foreseeable future.

Ironically, the biggest impediment to a merger between the two parties probably wouldn’t be the Liberal membership. The NDP, with its recent gains and current status as her majesty’s official opposition, might be tempted to ignore the logic of a merger because of their proximity to power. But their position right now is like that of an army that’s broken through enemy ranks and in a rush of excitement moved far ahead of its supply lines. Yes, it’s taken new ground, but it doesn’t stand much of a chance of holding it for very long, and it may ultimately be setting itself  up for greater casualties down the road. With no general and a bunch of inexperienced or under-qualified lieutenants, the NDP would be wise to beat a strategic retreat and reinforce its position. In other words, they ought to merge while they’re ahead.

The Liberals, meanwhile, would be giving up on more than a century of tradition, and there are going to be plenty of people within the party that won’t want to do that. But as the last eight years have showed time and again, the Liberal Party of Canada doesn’t stand for anything other than itself and its own preservation. Despite the varying contributions of three different leaders, it has been unable to craft a coherent identity for itself in the post-Chretien era. In truth, it’s been adrift for much longer than that – perhaps as long as former Prime Minister Trudeau has been out of office.

A merger between the Liberals and the NDP wouldn’t just be one of equals. It would be one of complimentary forces, a pairing whose whole would be greater than the sum of their constituent parts. The NDP would bring its vitality, its energy and its credibility with voters, while the Liberals would contribute their steadying influence, fiscal credibility and organizational heft. The NDP faction would force the Liberal faction to take stronger positions on issues, while the Liberals would in turn moderate the NDP’s more unrealistic ambitions.

It would be a difficult courtship process, to be sure, but it would have the potential to produce a very productive marriage, one in which the interests of progressive Canadians would be far better served than they are today. And it would also do service to Jack Layton’s view, expressed in his deathbed letter, that “we can be a better, fairer, more equal country by working together.” Surely, that’s something that members of both parties can get behind.