With little more than two months to go before Canadians head to the polls, the Liberals might have thought the SNC-Lavalin affair was behind them.

So much for that.

When the story initially broke in February, the impact on the Liberals' electoral fortunes was significant — an impact the party hadn't quite recovered from even before Ethics Commissioner Mario Dion published his damning findings yesterday.

Dion found Prime Minister Justin Trudeau violated the Conflict of Interest Act by trying to influence then-justice minister Jody Wilson-Raybould and get her to overrule a decision to not grant a deferred prosecution agreement to the large Quebec-based engineering firm.

It's an open question whether the Liberals will take another hit in the polls now that the SNC-Lavalin affair has made its way back into the news. It's also an open question whether they could survive another blow like that one.

In early February, before polls started registering the impact of the story first reported by the Globe and Mail, the Liberals enjoyed a four-point lead over the Conservatives. The CBC's Canada Poll Tracker estimated that the Liberals were still in a good position to win another majority government, even if reduced in size, and that they had a four-in-five chance of winning the most seats.

About three months later — after the fallout from the story, including the expulsion from caucus of former cabinet ministers Wilson-Raybould and Jane Philpott, had largely settled — support for the Liberals had cratered by seven to eight points. The Conservatives moved ahead with a six- to seven-point lead in the polls nationwide, enough to have them knocking on the door of a majority government of their own.

Trudeau might have suffered more of a blow than the Liberal Party itself. Polls by Abacus Data found that 44 per cent of Canadians had a positive impression of the prime minister at the end of 2018. By April, that had plummeted by 12 points to just 32 per cent.

Similarly, approval ratings polls at the end of 2018 and in early 2019 put Trudeau's numbers somewhere in the mid-to-high 30s. By the end of the spring, those scores had fallen to around 30 per cent, with twice as many Canadians saying they disapproved of the prime minister as those who said they approved of him.

Liberal numbers have been trending up

The comeback has been slow — but it appeared to have hit a tipping point over the last few weeks. On Aug. 12, the Poll Tracker put the gap between the Conservatives and the Liberals at just a single point. Leads of about six points in Ontario and 11 points in Quebec helped propel the Liberals ahead of the Conservatives in the seat projection for the first time since February.

Approval ratings had returned to the mid-30s, and a series of polls put Trudeau ahead of Conservative Leader Andrew Scheer as the person more Canadians want to see as prime minister.

The corner, it seemed, had finally been turned for the Liberals.

But will it be turned again?

Former minister of justice and attorney general Jody Wilson-Raybould was a leading figure in Justin Trudeau's government. But Trudeau's handling of her concerns about SNC-Lavalin and her subsequent departure from cabinet put Trudeau on the defensive for much of the winter and spring. (Adrian Wyld/The Canadian Press)

It's possible that Canadians' views of the SNC-Lavalin affair are already formed and that the conclusions of the ethics commissioner won't change anything — on the one hand, confirming the opinions of those who had long ago decided Trudeau had done wrong and, on the other, failing to shift the views of those who feel the prime minister acted appropriately in the face of potential job losses.

But it's also possible the report will chip away at the benefit of the doubt some of Trudeau's supporters have been willing to give him, particularly those who have returned to the Liberals over the last few months.

SNC-Lavalin affair's resonance faded

As the spring turned into summer, voters' minds had turned away from the SNC-Lavalin affair. In March, the Angus Reid Institute found 15 per cent of Canadians listing "ethics and accountability" as one of their top two issues facing Canada. The polling firm's latest sounding put that share down to just eight per cent.

Of course, both scores put the issue well behind others like the economy, taxes, health care and the environment — issues that are more likely to be voters' focus when they finally cast their ballots two months from now.

It did take the Liberals some six months to regain about half of the support they lost in the wake of the SNC-Lavalin affair, but election campaigns have a way of shortening the time required to shift public opinion.

In the coming weeks, the polls will reveal if the Liberals will once again have some catching up to do. Even if the blow is as bad as it was in the spring, they might have enough time to absorb it. The campaign has yet to begin and, yes, campaigns actually do matter.

But instead of launching that campaign with a little optimism and a bit of momentum after a tough six months, the Liberals might now find themselves back just where they started.

In the wake of a report on Prime Minister Justin Trudeau's ethics violation in the SNC-Lavalin case, The National's At Issue panel reconvenes to discuss how much the latest chapter in this controversy will hurt the Liberals in the upcoming federal election: