According to a riding poll taken before election day in Ontario, which is one week from today, Liberal Leader Steven Del Duca is behind the Progressive Conservative incumbent, Michael Tibollo, in Vaughan—Woodbridge, though by an amount that's within the poll's margin of error.

Del Duca has the backing of 42.4 per cent of leaning and decided voters, and Tibollo has 45.6 per cent, according to the Mainstreet Research poll, which has a margin of error of 4.4 per cent.

Del Duca lost Vaughan—Woodbridge in 2018 to Tibollo by 18 per cent of the vote. Tibollo, a lawyer, has held several positions in Progressive Conservative (PC) Leader Doug Ford's cabinet over the last four years.

When the PCs formed government in 2018, Tibollo was the solicitor general, but he was demoted after news broke of lawsuits against him, and of his involvement in a Ponzi scheme in the 1990s. He was shuffled to tourism, and later demoted to associate minister of mental health.

Political observers say the riding was always going to be challenging for Del Duca.

"I think that if Steven Del Duca could do it all over again, he probably would have asked (former Liberal leader) Kathleen Wynne to resign her seat, so he could have run in a byelection in Don Valley West, a riding that probably would have been much easier for the Liberals to win," said Karl Baldauf, a former senior aide in the PC government and a vice-president with the Macmillan Vantage policy group.

With a seat at Queen's Park, Baldauf argues, Del Duca could have built his public profile in a way he didn't have a chance to do.

"(In the last few years), he wasn't in the legislature, he wasn't going toe to toe with the premier every day, he wasn't able to demonstrate a strong posture in the (public) eye, because he wasn't in question period and he wasn't able to get daily media coverage in daily scrums."

Ashley Csanady, a senior consultant with Macmillan Vantage policy group and a Liberal supporter, disagrees.

"I think it makes sense for him to run where he lives, even if it's a tougher race," she said. "He's raising his kids there.

"Let's say he'd gone for the seat that's now formerly occupied by Kathleen Wynne. People would have criticized him for parachuting in, and that he doesn't live there and doesn't know the community."

Before a redistribution, Del Duca was elected twice in the former riding of Vaughan, which had different boundaries, by comfortable margins.

Federally, Vaughan—Woodbridge has been narrowly won by the Liberals since it was created before the 2015 election, with the Conservatives in a string of second-place finishes.

A loss in Vaughan—Woodbridge would raise questions about Del Duca's future as Liberal leader, Baldauf says.

"I think they'd probably be looking for new blood. Del Duca would have very few options, especially if he (wins fewer seats than) the NDP. If that's the case, there (will be) very little argument, I think, to keep him."

The PCs are ahead in the polls, in part because Del Duca and NDP Leader Andrea Horwath haven't made a case for change that's caught the public imagination, he argues.

"As Conservatives, we're happy that that's taking place, but, from an opposition perspective, they're really dropping the ball."

For Csanady, it depends on how the party does on June 2.

"For a party that's running third and doesn't have status, he's really run a strong campaign on a shoestring, so I don't see anyone immediately agitating for his removal."

As well, she points out, a PC victory would mean a fourth straight election loss for Horwath and a probable NDP-leadership race. The Liberals would be reluctant to let that compete for public attention with their own leadership process.

"If it's a situation where we've won a bunch of seats that we didn't otherwise have, but Del Duca didn't win his seat, I think that they'd have him stay on, and he'd take another shot at another riding, or wait for a byelection."

Party leaders who lose in their ridings and try to win a seat elsewhere have had mixed success, however.

Former PC leader (and current Toronto mayor) John Tory tried in 2009 after his 2007 loss in Don Valley West, after which he was forced to be Ontario's opposition leader from outside the legislature.

PC veteran Laurie Scott resigned to open Haliburton—Kawartha Lakes—Brock for Tory in 2009 through a byelection, which the latter then lost. With the single exception of that byelection, the riding has been strongly PC since it was created in 1999, and PC ever since.

Tory's campaign attracted about 9,000 fewer PC votes than would be usual in the riding, while the Liberals performed about normally and won. His failure was attributed to local voters' annoyance at being offered a "parachute candidate" with no roots in the riding. Tory resigned as party leader shortly afterward.

Scott returned in the 2011 election and has represented the riding ever since; she's running again in this election.

Former B.C. premier Christy Clark, on the other hand, pulled it off twice, though on both those occasions she had the leverage of being a premier without a seat.

This Mainstreet Research poll was conducted from May 20 to 25. A sample of 486 people was interviewed by automated telephone interviews. The poll is accurate to within ±4.4 percentage points, 19 times out of 20. The poll is weighted for age, sex, and region to be representative of the entire adult population of Canada.

Beyond the margin of error, all polls are subject to other sources of potential error, including coverage error. Riding surveys are particularly susceptible to coverage error; the smaller the population being surveyed, the greater the likelihood of coverage error.

The sample in this case yielded results that are consistent with the modelling, except for the gender demographics, where PCs led among female respondents and Liberals led among male respondents. The deviation is within an acceptable margin of error.

The poll is not intended to predict what will happen in the future; it's a snapshot in time of what voter intentions were at the time of the fielding.

Mainstreet Research is part owner of iPolitics and QP Briefing.

Riding poll: Del Duca behind in Vaughan—Woodbridge

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