When Maclean's magazine published a story last week about Thomas Mulcair's past flirtation with the Conservatives, it marked the start of an open season on the NDP Leader that's expected to continue into the fall, if his party remains high in the polls.
Despite the NDP's apparent momentum, Mr. Mulcair remains a little-known entity to many voters. His rivals will attempt to define him before he gets a chance to fully define himself.
Here's a rough guide to some of the attacks the man who would be the country's first New Democratic prime minister should be prepared for over the next three months. Some of the accusations he might face will contradict others, and some could backfire against the parties levelling them.
He's an old-school Quebec politician
Much of the NDP's appeal is predicated on being the most credible change agent, partly because it's never been in power. But if his federal party doesn't have much baggage, opponents might try to find some in Mr. Mulcair's 13 years in Quebec's National Assembly.
Asked recently how his party would go after the NDP if it really needed to, a Conservative official started talking about Mr. Mulcair's time as a minister in Jean Charest's scandal-plagued provincial Liberal government, which faced corruption allegations. The Conservative also noted a story about Mr. Mulcair being offered a suspicious-looking envelope by the since-jailed former mayor of Laval – something the Tories have made passing attempts to highlight previously – and his reported remortgaging of his home 10 times.
Mr. Mulcair has never faced corruption allegations, he was the one who later reported the suspicious envelope (which he suspected contained cash and he didn't accept) to police, and it's unclear what relevance the mortgages have. As they try to pick up a few Quebec seats, the Tories might not do themselves a favour by implying guilt by association on the basis of Mr. Mulcair having served in his province's government. But they have evidently given some thought to doing that.
He's a threat to national unity
Justin Trudeau has already sharply criticized Mr. Mulcair's (recently reiterated) support for the Sherbrooke Declaration – an NDP policy that, among other things, calls for Quebec to be allowed to separate with a "50 per cent plus one" referendum vote, rather than the "clear majority" required by the Clarity Act.
Behind the scenes, there are Liberals who want to push harder to raise the issue's profile in the rest of Canada. With Pierre Karl Peladeau the most sovereignty-focused Parti Québécois Leader since the 1990s, the Liberals could become more vocal in warning about the dangers of a PQ election win with the NDP in power federally.
As with the insinuations the Conservatives seem to be considering, going after Mr. Mulcair on unity could turn off voters in Quebec. The NDP's response, based on a conversation this week with an adviser to Mr. Mulcair, might be to press Mr. Trudeau to specify what number constitutes a "clear majority."
But polls suggest that, outside parts of Montreal, the Liberals are struggling badly in Quebec regardless. If that continues, they could decide it's a tradeoff they have to make.
He won't stand up enough for Quebec
It's an unlikely coincidence that Mr. Mulcair's recent Sherbrooke Declaration talk followed Gilles Duceppe's return to the Bloc Québécois helm. With little time to breathe life back into his party, Mr. Duceppe will do everything he can to persuade nationalist voters who helped elect 59 Quebec NDP MPs in 2011 that their interests aren't being represented.
Beyond sovereignty, the Bloc is trying to exploit the NDP's openness to the proposed Energy East pipeline that would run from Alberta to New Brunswick – contending that after fighting pipelines that would run through British Columbia, the NDP is less concerned by one through Quebec. And it can also be expected to make hay of Mr. Mulcair's opposition to restrictions on wearing niqabs, painting it as unwillingness to protect Quebec's identity.
The challenge for the NDP will be to deflect these attacks without saying things that hurt it elsewhere in the country.
He's a left-wing risk
The least surprising attack on any NDP leader is that he or she would raise taxes and jeopardize the economy.
Although not the most traditional New Democrat, Mr. Mulcair offered fodder during a radio interview by proving unable to correctly identify the current level of the corporate tax rate he wants to raise.
The Conservatives are the ones to go hard at him on such things, as well as alleged softness on foreign policy. The more Mr. Mulcair looks like a threat to them, the more they'll step it up.
He's a phoney
At the least, Mr. Mulcair's opponents will try to poke holes in his smiley new demeanour by drawing attention to his previous reputation for being a mercurial loner. And even as the Conservatives try to paint him as too left wing, other parties might also try to sow doubts about whether he actually aligns with the values of the party he leads.
Mr. Mulcair was, after all, a minister in a centre-right provincial government. Although he left that government over a dispute about environmental policy, he did not necessarily have a reputation for being a left-wing force within it.
Along with the resurfaced story about his talks with the Conservatives, that could actually serve to reassure some voters that Mr. Mulcair is in the mainstream. If other parties aren't careful, various attacks could just wind up bouncing off each other without forming a coherent narrative against him. But it remains to be seen how agile Mr. Mulcair might be in responding to a level of scrutiny he hasn't yet faced.