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Just a few months ago, NDP leader Tom Mulcair was thought to be doing badly. His summer campaign to bring down the Senate — the Roll Up the Red Carpet Tour — was written off by pundits as a losing effort. One analyst went so far as to say Mulcair’s only hope was to fire his advisers.

How strange that all looks now. With Stephen Harper showing himself to be a serial truth abuser, with Justin Trudeau gunning himself down with rash remarks, the NDP leader is Ottawa’s undisputed starring act. In a town that doesn’t have much of it, he is the guy with the gravitas.

A big and justified fear gripped New Democrats not long ago: With the Liberals catapulting to the top of the polls under Trudeau it appeared the Dippers were returning to their traditional spot in third place. That Orange Wave breakthrough in the last election? Just an aberration.

That isn’t at all certain now — not with the way Mulcair has taken over the show. He has become the dominant performer in the House of Commons. He has made mincemeat of the Conservatives on the Senate scandal. He has shown Trudeau to be the novice that he is and it shows in his rising approval ratings.

Mulcair may well end up having a lasting impact on the practice of politics in Ottawa. With short, pointed queries demanding straight answers, he has revitalized question period. By watching him, opposition members are learning lessons they should have learned long ago. Stay away from long-winded lectures. Demand specific information. Make the prime minister and colleagues like Paul Calandra look pitiful in their attempts to evade and stonewall.

Mulcair may well end up having a lasting impact on the practice of politics in Ottawa. With short, pointed queries demanding straight answers, he has revitalized question period. By watching him, opposition members are learning lessons they should have learned long ago.

Mulcair’s decision to put his QP focus on the Senate is being vindicated by events. He realizes his best chance of bringing this government down is on the issue of political corruption. Though the hush-money scandal is off the front burner this week, it’s destined to return soon. The RCMP investigation will make certain of that — as will further probing by the opposition next week of the many holes in Harper’s story.

The Conservatives came forward with some good news this week — the projection of a $3.7-billion surplus by 2015. That surplus might have been almost twice as large, had the Tories not mislaid that $3.1 billion in public safety funds. Auditor General Michael Ferguson found no spending trail for that money and no explanation for where it went. The opposition parties should be all over this file but they seldom raise it.

Mulcair was suffering in public opinion, according to pollsters, because he was projecting too strongly the image of an angry attack dog of the left, predictably going after the government for anything and everything. But the seriousness of the Senate scandal suits his prosecutorial approach; voters can see how Mulcair shines in holding Harper to account.

He’s been lucky, too. The Conservatives dug themselves in deeper with Harper’s decision to push for the senators’ suspension before the police investigation was complete. That prompted Mike Duffy to fight back — and fight back he did. Harper didn’t learn from history: Liberals regret that Paul Martin couldn’t leave it to the police to look into the sponsorship scandal. Instead, he appointed an inquiry. Remember how that went?

He’s been lucky in his rivals as well. Justin Trudeau’s attempts to clarify his words of praise for the Chinese state went nowhere; the media paid little attention to his elaboration. The CBC’s Terry Milewski pointed out that Harper himself has praised China and its wonderful economic gains. But the damage was done.

The Liberals still sit atop the opinion polls but pollsters see slippage on the way. A measure of how the climate is shifting may come with the four by-elections on Nov. 25 — one in Toronto, one in Quebec and two in Manitoba. The NDP has not been favoured to win any. But with recent developments they may now have a chance in Ontario and Quebec. Even if they don’t win, the results should at least see them trending upwards.

For the Conservatives, none of this is a bad thing. NDP gains come mainly at the expense of the Liberals, dividing up support on the progressive side, which serves the Tories well. The last thing Harper wants is an NDP collapse. The way Mulcair’s going, he needn’t worry.

Lawrence Martin is the author of 10 books, including six national bestsellers. His most recent, Harperland, was nominated for the Shaughnessy Cohen award. His other works include two volumes on Jean Chrétien, two on Canada-U.S. relations and three books on hockey.

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