Alberta NDP Leader Rachel Notley says she has not spoken to federal Leader Thomas Mulcair for months. She says she takes her cue from Albertans only. There are policy differences between the provincial and federal parties.

In any case, good showings by provincial parties don't often translate to better results for the federal party in the province in question. Often the opposite is the case. In Ontario, the opposite is almost always the case.

All that said, a win by Ms. Notley today in the Alberta election would be a major boost for Mr. Mulcair and the federal party – and one that comes at a critical time.

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Should the leftists do the gobsmackingly unthinkable in what is still considered Canada's most right-wing province; should they topple one of the most formidable political dynasties in our history, the NDP brand will be strengthened across the board just months before a federal election.

This won't translate into a big harvest of seats for the federal party in Alberta. Prime Minister Stephen Harper isn't fumbling away his base there like the provincial Conservatives are. But it will provide a shot of credibility and momentum for the New Democrats. Voters who have paid little attention to them or who have been caught up in old stereotypes – Bolsheviks! No thank you – will give the party a new look. If the NDP isn't too scary for Albertans, who is it too scary for?

The fact that Ms. Notley's policies are more moderate will likely help broaden the Dipper tent. That she is personable and charming is a plus for the NDP image generally. Charisma in that party has rarely been in abundant supply.

We recall that Bob Rae's upset victory in 1990 in Ontario for the New Democrats hardly served to improve the party's overall image. He faced a deep recession and mishandled it. But the comparison is not a good one. Before that election, the NDP was a strong force in Ontario. In Alberta, the NDP hasn't won more more than four seats in the past six provincial elections. Today's upset, should it happen, would be more astounding. Ms. Notley will have a terribly inexperienced cabinet and it is bound to create problems. But she'll have a honeymoon of a few months. There likely won't be enough time to screw up badly before the federal election. Momentum will still be there for the federal party to ride.

A victory by her would be grim news for both the federal Conservatives and Liberals, but worse for Justin Trudeau's Liberals. Mr. Harper would loathe seeing the NDP at the controls of the province that is his base and his party's base. But he'll likely hold his Alberta seats. Across the country, he knows that a rise in New Democratic fortunes comes mainly at the expense of the Liberals. The more vote-splitting among progressives the better. If the two main opposition parties are neck and neck, Mr. Harper's chances of winning are enhanced.

Some are predicting that Albertans will get cold feet today and revert to the party that has governed them for 44 years in succession. But the NDP polling lead in Alberta is twice the size of other parties that have been in front in other recent provincial elections only to be stunned on election day.

The shock waves that will be sent through the system by an Alberta NDP triumph are such that the federal party could very much narrow the gap on the second-place Liberals. In the election campaign, the NDP, which currently has 59 more seats than the Grits and has the most formidable debater in Mr. Mulcair among the party leaders, could well become, like in the previous campaign, the go-to party for progressives desperate to prevent another Harper victory.

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If that happens, and if you wish to let your imagination run wild, consider this: Come the fall, it is not out of the question that we could have an NDP government both in Alberta and in Ottawa.

Stranger things have not happened.