Canada and the U.S. share the world's longest border. Here's how the election could affect it

Spend just a few minutes at the border between Canada and the U.S. – the world's longest – and you'll see why trade is a vital lifeline.

CTV National News got to the Windsor, Ont. border crossing shortly after dawn at the beginning of a multi-state road trip to witness dozens of transport trailers at a duty-free stop on the Canadian side fueling up and passing by.

Most of the goods they're hauling are covered by a trade agreement between three countries: Canada, the U.S. and Mexico. Formerly known as NAFTA, the trade agreement is now called the Canada-United States-Mexico Agreement (CUSMA) by the Canadian government.

Last year $3.6 billion in trade flowed through the border daily and 400,000 crossed it for business, tourism, or to see family and friends.

Though they have no stake in voting, truckers on the Windsor side describe the election as critical. "As a Canadian, as a border city, it depends on us a lot. Our economy. Our jobs. Our income," Behar Berbatovci said. "We had Donald Trump before but I'm not a fan. He started putting tariffs, causing war between the trades."

Another Canadian trucker who chose not to give his name, says he was better off when former U.S. president Donald Trump was in power.

"When Trump was there, the trucking business was high, we were getting good money. Right now, it's bad," said the trucker, adding he made thousands more each month at that time.

The Trump administration preceded the pandemic that ushered in economic headwinds, closed borders and impacted supply chains throughout the world.

And now, for Canada, each presidential candidate could bring unique challenges to the bilaterial relationship.

This year, for the first time in decades, the truckers' union - the Teamsters - opted not to endorse either candidate.

Trump has vowed to renegotiate the trade deal in 2026. He oversaw the revision of NAFTA already during his presidency.

The negotiations that began in 2017 to replace NAFTA brought Canada-U.S. relations to a low-point, as Trump hurled insults(opens in a new tab) at Prime Minister Justin Trudeau and slapped hefty tariffs on Canadian aluminum and steel(opens in a new tab).

"I terminated NAFTA. That's a pretty big thing," Trump said earlier this month. "A lot of people said it would be impossible to do. I got it done, and we have a great deal now. What we have to do is make it much better even, and we'll be able to do that very shortly."

Trucks cross the Ambassador Bridge from Windsor, Ont. into Detroit, Mich. (Paul Sancya / The Associated Press)

The new agreement included more U.S. access to Canadian supply managed sectors like dairy, allowed for cheaper online cross-border shipping and required higher levels of North American content in vehicles.

U.S. Vice President Kamala Harris has also telegraphed a renegotiation of the agreement if elected. She was one of 10 senators who voted against the updated Canada, U.S., Mexico trade deal because she wanted more environmental protections.

"Looking at the policies of both Trump and Harris coming into this election, with regards to trade, they're both protectionists – one with subsidies, the other with tariffs," said Stephen Laskowski, President of Ontario's Trucking Association.

"With these types of issues, protectionism has been around for 20, 30 years, so it's a matter of learning to deal with it."