How do you know it's effectively over for a political institution like the NDP, despite lingering vital signs? The critical point is the emergence of a plausible replacement, in this case the Greens under Elizabeth May. They're a presence in Ottawa and now rival the NDP in polls.

Till then you don't want to imagine it. It's like the CBC: you may not like it but it's needed. With someone else filling that slot, even in a sharply different way, their departure becomes thinkable.

You start noticing what they're not, and haven't been for a while. At their start, in the Depression of the '30s, as the CCF, they knew they had the answer to the questions the country was asking: How did we get into this mess and how do we get out? The answer was something like socialism or co-operation.

In recent years they don't show that confidence -- never mind what the specific answers might be. They're more like: "We're a grown-up party too and dammit, we deserve our turn."

That was the tone of Thomas Mulcair's 2015 campaign. When candidates in the recent leadership race were asked what distinguishes their party from the Liberals, none said: We have the answer to what the country needs -- as Elizabeth May surely would have. Their responses were pathetic. "We mean what we say … We follow through … We have principles … They just want power …" Pathetic, and laughable.

You start noticing other symptoms of decline, like the peculiar lassitude of Ontario's NDP. Leader Andrea Horwath was ideally situated to take the populist piss out of Doug Ford and win last year: a young, feisty single mom from the industrial wasteland of Hamilton, decimated by free trade. But she showed no real fever for the role. Since then MPP Marit Stiles has registered more.

They've held zero national fundraisers this year, says Elections Canada. Their crucial union support has waned. Unifor's Jerry Dias was seduced away by dinners with Gerry Schwartz and consultations with Chrystia Freeland. A quarter of their MPs aren't running again. Svend Robinson has returned from the past to run, he still seems to have the fire. But why does he stand out for that?

When did the decline begin? The free trade election of 1988, I'd say. Ed Broadbent was positioned to become PM but wavered on opposing the trade deal, for fear of sending support to the Liberals, and helped hand power to Tory Brian Mulroney, who rewarded Broadbent with a pleasant international gig.

Then came the wasted leaderships of Audrey McLaughlin and Alexa McDonough, of whom the party seemed to expect nothing. Then Jack Layton. He was serious about power, helping purge "socialism" from their constitution. His first three elections achieved little though the last, due to Quebec's unique way of deciding to vote tout ensemble, made him opposition leader.

Then Mulcair, who vowed not to run deficits -- at which point Liberals say they knew they'd won. It was crazy. The NDP's main appeal had been their perceived fealty to principle -- whether it was true or not. Leader Tommy Douglas even bucked many of his own members to oppose military rule in 1970.

The desertion of past principle is ironic since the "left" position has surged back, especially among the young. They aren't prey to the mythos of private property for good reasons: they won't have much. They don't expect to own houses, cars or even bikes -- and have decided it's fine to share. Not just socialism but a "co-operative Commonwealth" -- the CC in CCF -- might make sense to them.

But forget the past. What youth are most serious about is the present, in which they're starting to drown. Urgency may be the socialism of today.

The Liberals speak well on, say, democratic reform, but did nothing about it when they had the chance. Same with climate catastrophe or ongoing water disaster in Attawapiskat, which roared back this week. A Liberal mouthpiece said they'd "be travelling up to the community as early as next week.'"

That's their idea of speed -- except when SNC-Lavalin's involved. Then they become The Flash.

If there's any future for the NDP (versus ENDP) it might be as the UDP: the Urgent Democratic Party.

Rick Salutin writes about current affairs and politics. He is based in Toronto. This column was first published in the Toronto Star.

Photo: Ontario NDP/Flickr