"I will be a president who leads and listens, who is realistic, practical and has common sense and always fights for the American people," Harris said as she formally accepted her party's nomination.

"From the courthouse to the White House, that has been my life's work."

Harris spoke about her life, upbringing and career while sending a warning about a second Trump presidency. The speech was an introduction not just to party faithful but all of America at a pivotal moment for Democrats to reach beyond the convention walls.

Trump posted continuously on his Truth Social account throughout the speech criticizing the vice-president's record.

"SHE LED US INTO FAILING NATION STATUS!" the former president posted.

The outcome of the election will have impacts beyond America's borders, said Bruce Heyman, who served as ambassador from 2014 to 2017. He gave Canada a "tsunami warning."

"If Donald Trump is elected president, Canada is at great risk," he said, pointing to Trump's stand on trade, abortion and clawing back environmental policies.

Heyman's comments came on the sidelines of the convention, where thousands of party faithful rallied behind Harris and basked in the excitement building around the vice-president since she ascended to the top of the ticket.

The enthusiasm, while palpable in the halls of the convention, does not guarantee a win in November. Heyman said it is critical that Americans around the world ensure their vote counts.

He said there are at least 6.5 million eligible voters living in other countries, mainly in Canada and Mexico.

When President Joe Biden was elected in 2020, Heyman said votes from Americans abroad played a key role in clinching the White House.

Heyman said much of that support was shored up through outreach efforts. As a result, the number of Americans who voted from outside the country in 2020 was up 73 per cent over the 2016 election, and half of those votes went to battleground states.

"Americans in Canada: you can be part of the decision of who wins the election," Heyman said.

The convention's Thursday theme was "For our Future" and the former ambassador to Canada said the election could prove critical for the future of Canadians, too.

Heyman, who was appointed under Obama, became well-known for strengthening the relationship between Canada and the U.S. under both former prime minister Stephen Harper and Prime Minister Justin Trudeau.

Heyman and his wife Vicki left as Trump took power but remained connected to Canada, even writing a book about their experiences with Canadian diplomacy. They have since supported Democratic campaigns.

The first Trump administration proved tumultuous for Canada, Heyman said, with the former president's policies affecting more than trade.

Thousands of people in the U.S. who were afraid of rumours of mass deportations started travelling into Canada outside of regular border crossings.

Trump has promised to deport 11 million undocumented immigrants if he gets a second term. Heyman said he believes that people, once again motivated by fear, would start to flee north in even higher numbers.

"I don't believe Canada is prepared for those kinds of numbers to come across the border," he said.

If bans against abortion expand further in the U.S., Heyman warned, people may look to Canada for help. If Trump claws back environmental policies, it could affect Canada's investment into green technologies, Heyman said.

And if a Trump administration removes support from NATO and other alliances, Canada's stature around the world would diminish alongside the U.S., Heyman said.

He added that Canada would likely have to fast-track its NATO defence funding commitments to avoid Trump's wrath. Trudeau said last month that Canada expects to hit its target of spending two per cent of national gross domestic product on defence by 2032.

"I think that for Canada, it's a high risk -- the Trump administration -- if he implements the policies he says he wants to implement," Heyman said.

"And the greatest risk for Canada is he does it all at once as ... swarm tactic to attack Democrats."

The first Trump administration showed the former president can make "enormous policy decisions on a whim based on which leaders he likes or what he thinks is best for him personally," said Matthew Lebo, a specialist in U.S. politics at Western University in London, Ont.

"Being next door to the world's biggest economic and military power and watching them slide away from democracy should raise alarm bells."

Global leaders have likely kept an eye on the convention and Democrats gave some insight into Harris' foreign policy agenda.

The vice-president said she was working with Biden to end the war in Gaza so that Israel is secure, hostages are home and Palestinians can realize their dreams of self determination.

She also committed to standing with Ukraine and NATO.

"Kamala Harris knows that standing with our allies means standing up for Americans," Arizona Sen. Mark Kelly said during his remarks.

This report by The Canadian Press was first published Aug. 22, 2024.