'It's nerve-racking': Trump's trade talk casts cloud over sunny economic times in Windsor, Ont.

"Windsor is back," declares Stephen MacKenzie.

The CEO of the southwestern Ontario city's economic development corporation says the proof is in his files.

He pulls out a document announcing a $70-million investment in a local shopping centre.

He quickly recites a list of businesses that are expanding and projects that are pending.

"All of the signs of an economy that's continuing to move," he says.

But MacKenzie has another file a thick one.

It's filled with statements, tweets and other clues as to what President Donald Trump might have planned for the U.S.'s business relationship with Canada.

After years of doom and gloom, Windsor is booming, but MacKenzie and other folks in the border town worry Trump might try to stop the good times in their tracks.

'Worst-case scenarios'

His "America First" mantra, his very public tactics to pressure companies to keep jobs in the U.S. and his vow to renegotiate NAFTA are all heard loud and clear in this city.

"It's nerve-racking," MacKenzie says. "Human nature has a habit, in a vacuum of not knowing, to jump to the worst-case scenarios."

In thoseworst-case scenarios, tariffs on the auto industry pop up and Windsor, once again, spirals downwards.

• Tariffs could be 'lethal' to Windsor, says Fiat Chrysler CEO
• Minister stresses U.S. Canada relationship amid Trump tax threats

The city has endured its share of misery since the Great Recession. It took years to recover from the near-collapse of the auto industry in 2009. Unemployment spiked above 15 per cent.

It's now less than six per cent, below the national average. And the city's economy is growing faster than in most places in the country.

'We are non-stop'

Construction worker Carla Somogyvary says she has all the work she can handle.

"We are non-stop," she says. "As soon as we are done a house, there is another house to build and another house to build."

It's leading to labour shortages a stunning development in a city that struggled for so long.

Ben Klundert, who owns a home construction company, expects to build a record number of houses this year.He says he could build even more if only he could find more skilled workers.

"They are hard to find," he says. "We could always use another four or five."

Windsor's rebound started at Fiat Chrysler's massive minivan plant. The company poured more than $1 billion into the facility. The recently completed upgrade created more than 1,000 jobs. And each auto assembly job is estimated to help createnine more jobs elsewhere in the economy.

Free flow

It has led to a surge in confidence in a community where there wasn't much before.

But, for some, the new Trump administration has created a cloud of uncertainty.

• Canada's not focus of Trump's NAFTA talk but it could be 'collateral damage'

Windsor depends on the free flow of cars and car parts between Canada and the U.S., usually via the Ambassador Bridge, which towers over the Detroit River.

So far, the main target of Trump's tough trade talkhas been Mexico. But there's concern Canada couldalso be threatened with tariffs or other restrictions.

"It could change things fairly drastically," auto industry expert Tony Faria says. But he believes Trump or his advisers will realize, if they haven't already, that disrupting the highly integrated auto industry supply chain would do damage on both sides of the border.

"You don't want to willy-nilly do something where you're in fact promising to create U.S. jobs" but could end up accomplishing the opposite, he says.

Back in his office, Stephen MacKenzie admits to being "unsettled" by the aggressive trade talk from the U.S.

But he does more than just worry. He keeps adding to his file of Trump clues.

It's vital information for a city that's hoping the good times keep rolling.