Some of the most closely watched races on election night will be in ridings where high-profile cabinet ministers are on the ballot — and at risk of losing their seats.

This unpredictable campaign has put several Liberal ministers in tight races, fighting for their political careers.

One of those battles is being waged by long-time party stalwart and cabinet minister Ralph Goodale, who is working to hold his Regina-Wascana riding in Saskatchewan against Conservative candidate Michael Kram. Goodale, who has been the lone Liberal MP in the province for more than a decade, has long been a primary target for his political opponents.

Hoping to capitalize on regional voter frustration over the Liberal government's carbon tax and its failure to get a new oil pipeline to tidewater built during its mandate, the Conservatives have dispatched prominent Conservatives like Alberta incumbent Michelle Rempel and Sen. Denise Batters to campaign in the riding.

So excited to be doorknocking for <a href="https://twitter.com/MichaelKramSK?ref_src=twsrc%5Etfw">@MichaelKramSK</a> in Regina-Wascana tonight. <a href="https://twitter.com/denisebatters?ref_src=twsrc%5Etfw">@denisebatters</a> and I are finding so many people who are saying they aren't voting for Ralph! <a href="https://t.co/lg403AJpft">pic.twitter.com/lg403AJpft</a> —@MichelleRempel

Conservatives see an advantage in the fact their leader, Andrew Scheer, holds a Saskatchewan seat. They also see Goodale as uniquely vulnerable due to some past controversies on his watch as public safety minister — including the government's $10.5 million payment to former Guantanamo Bay detainee Omar Khadr and the decision by the Correctional Service Canada to transfer child murderer Terri-Lynne McClintic to a healing lodge.

Still, one close political observer says Goodale shouldn't be losing sleep.

Left: Liberal candidate Ralph Goodale. Right: Conservative candidate Michael Kram. (Justin Tang/The Canadian Press, CBC)

Jim Farney, a political science professor at the University of Regina, said he thinks Goodale's seat is safe — because he won by a significant margin against the same Conservative candidate in 2015, and because while he's an MP in a province that's "deeply anti-Trudeau," he's represented the riding federally or provincially for decades.

"He's got a record of ensuring that Regina projects get funded, a deep community network and an independent personal brand," Farney said. "I don't think that efforts to brand him a Trudeau loyalist have been very successful. So, closer than last time, yes, but I think he'll still win."

Amarjeet Sohi is also in a close race in the Alberta riding of Edmonton Mill Woods. As natural resources minister, he was the face of the Liberal government on controversial pipeline issues. He now faces Conservative candidate Tim Uppal, who served as an MP from 2008-2015.

Left: Liberal candidate Amarjeet Sohi. Right: Conservative candidate Tim Uppal. (Fred Chartrand, Sean Kilpatrick/The Canadian Press)

The contentious nature of the Trudeau government's approach to pipelines has ramped the risk factor for Sohi. Cabinet ministers enjoy high public profiles and opportunities to show leadership on policy issues, factors which tend to favour them at election time. But that enhanced profile can be a double-edged sword, said Liberal commentator Greg MacEachern.

"When a cabinet minister loses, it's quite significant and people tend to look at reasons why … were there unpopular decisions made that can be connected to your time?" he said.

MacEachern said a cabinet position comes with a heavy workload, which can undermine the candidate's perceived "visibility" in the riding. An efficient constituency staff in the riding can make up for that by tending to the needs of the riding while the minister is unavailable, he said — which typically makes the trade-off work to the minister's advantage.

"Definitely, a hit on a newscast that's going to be viewed by thousands of Canadians, thousands of your own potential voters, is far more important than being seen at the latest ribbon cutting on a Saturday morning," he said.

Setting sights on prominent Liberals

The Bloc Québécois under Leader Yves-François Blanchet is enjoying a surge in support. That's posing a threat to high-profile Liberals in Quebec, such as Jean-Yves Duclos, the cabinet minister (for families, children and social development), who is facing off against BQ candidate Christiane Gagnon in Quebec City. Gagnon held the riding from 1993 to 2011, when it flipped to the NDP before going to the Liberals in 2015.

Left: Jean-Yves Duclos. Right: Christiane Gagnon (Sean Kilpatrick, Jacques Boissinot/The Canadian Press)

Lydia Miljan, a political science professor at the University of Windsor, said cabinet ministers enjoy an "incumbent advantage" — and when they lose, it's a sign of voters' dissatisfaction with their work or the work of the government as a whole.

"Overall, [ministers] are symbolic of the government itself. And it's a clear way for that riding in particular to say, 'We're not happy with the choice we made last time, and we want a redo,'" she said.

Another minister who has been the Liberals' torchbearer on a controversial file is Catherine McKenna. As environment minister, she has been tasked with selling Canadians on the benefits of a carbon tax — a key part of the Liberal government's climate change action plan.

Left: Liberal candidate Catherine McKenna. Right: NDP candidate Emilie Taman. (Andrew Vaughan/The Canadian Press, CBC)

McKenna is working to hold her Ottawa Centre riding against NDP candidate Emilie Taman, a former federal prosecutor and law professor.

The riding, which includes the parliamentary precinct, had the highest voter turnout in the country last election, with 82 per cent of eligible voters casting a ballot.

NDP MP Paul Dewar, who died in February, represented the riding from 2006 to 2015, when McKenna won it by more than 3,000 votes.

Amanda Bittner, a political science professor at Memorial University, said sitting cabinet ministers usually have a better shot at re-election because, in a culture where many people tune out politics, name recognition counts for a lot.

Bittner said it can be a "serious blow" for an incumbent governing party to lose a high profile cabinet minister on election night.

"If McKenna loses her seat, for example, that says not only something about her appeal to voters, but is also potentially a commentary on the Liberal climate policy and track record," she said. "Given what a salient issue [the environment] is for Canadians right now, I think that if she loses her seat it will be a big deal."

Left: Jane Michael, Conservative party candidate for Burlington. Right: Karina Gould, Liberal party candidate for Burlington. (Karen Gould/Twitter, Adrian Wyld/The Canadian Press)

Karina Gould, the democratic institutions minister, is up against Conservative candidate Jane Michael, a business owner and former school board trustee, in the riding of Burlington, Ont.

Gould won the seat by a narrow margin in 2015. It was won by the Conservatives in the three previous elections.

Bernadette Jordan, the minister for rural economic development, faces Conservative Rick Perkins in the Nova Scotia riding of South Shore-St. Margaret's. He has been tapping into anxiety around the Liberal policy for protecting marine areas, which could affect groundfish, lobster and scallop fishing industries.

Left: Conservative candidate Rick Perkins. Right: Liberal candidate Bernadette Jordan. ( CBC, Andrew Vaughan/The Canadian Press)

Jordan is the first woman from Nova Scotia to become a federal minister, and one of only two Liberals to represent the riding in the past 62 years.

She has said her second federal campaign is a "tougher sell" than the first because the incumbent government must defend its record.

Two other cabinet ministers are seen to be facing tough challenges in the current campaign. Harjit Sajjan (defence) is up against Conservative candidate Wai Young in Vancouver South; she held the riding from 2011 to 2015. Maryam Monsef (status of women) is running against Conservative candidate Michael Skinner in Peterborough-Kawartha.