President John F. Kennedy stood before Canadian lawmakers elucidating the important relationship between the two countries: 鈥淕eography has made us neighbours. History has made us friends. Economics has made us partners.鈥�

鈥淎nd necessity has made us allies,鈥� Kennedy said in a 1961 address to Parliament.

But behind the scenes, the relationship between the charismatic Kennedy and then-prime minister John Diefenbaker was toxic.

With the looming United States election, the future of who will be at the helm of the bilateral relationship remains unclear, but Canada cannot escape the geopolitical pull of its closest neighbour.

While some presidents and prime ministers have been on friendly terms, the shared geography and history hasn鈥檛 stopped clashes between others.

鈥淲e have a long history of presidents and prime ministers hating each other鈥檚 guts鈥� and yet the system works,鈥� said Aaron Ettinger, a political science professor at Carleton University.

Experts say incompatible personalities won鈥檛 irreparably harm the relationship, but it can make it harder for Canada.

鈥淚t鈥檚 very difficult to operate when you have outright antagonism between the leaders 鈥� and that is less a function of ideology and more a function of personality,鈥� said Laura Dawson, an expert on Canada-U. S. relations and the executive director of the Future Borders Coalition.

That became clear during the first Trump administration when the former president scrapped the North American Free Trade Agreement. Negotiations of it鈥檚 replacement, the Canada-U.S.-Mexico Agreement, were marked by public spats between Prime Minister Justin Trudeau and former president Donald Trump.

Trump called Trudeau 鈥渨eak鈥� and 鈥渄ishonest鈥� after the prime minister criticized the president鈥檚 2018 tariff actions at the G7 summit in Quebec.

Robert Lighthizer, Trump鈥檚 trade representative, recounted in his book that U.S.-Canada relations were 鈥渁t their lowest ebb since the failed American invasion of Upper Canada during the War of 1812.鈥�

The following year there was another blow-up when Trudeau and other NATO leaders appeared to be on video talking about a Trump press conference. The former president called the prime minister 鈥渢wo-faced.鈥�

While the relationship between the leaders was publicly rocky, behind the scenes CUSMA was successfully negotiated. Deputy Prime Minister Chrystia Freeland called the agreement a 鈥渧ictory for all Canadians,鈥� and experts say it was more moderate than Trump originally threatened.

Whoever takes the White House will be in charge during trade pact鈥檚 2026 review.

Trudeau is a political veteran now, Dawson said, and is more prepared for a possible second Trump administration.

鈥淲e know that Trump-Trudeau is not a good fit,鈥� Dawson said. 鈥淏ut I鈥檓 sure that Trudeau will figure out a way to make it work.鈥�

Most experts say Kamala Harris鈥� personality would be a better match with Trudeau. It鈥檚 been reported they already have a good relationship and many of their policy goals align. He originally ran on 鈥渟unny ways鈥� and she kicked off her campaign with 鈥渏oy.鈥�

The vice-president also spent part of her youth living in Canada, although observers say the impact of her teenage years in Montreal is probably overstated.

鈥淗arris would obviously be easier for probably anyone to get along with,鈥� Dawson said. 鈥淏ut getting along only goes so far.鈥�

Harris has been campaigning on her vote against CUSMA, saying it didn鈥檛 do enough to protect U.S. workers, and is expected to follow the Biden administration鈥檚 Buy American procurement rules.

There鈥檚 another outcome to consider: a change in Canadian leadership. A general election must be held by October next year, but it could come sooner if the Liberals lose the confidence of the House.

The Conservatives have long held a lead in the polls amid high inflation, an exodus of Liberal ministers and uncertainty over Trudeau鈥檚 political future.

鈥淲e have a whole lot of turnover in the works coming up in the next two years between Canada and the United States,鈥� Ettinger said. 鈥淎nd it鈥檚 possible that we have two leaders who have never met one another.鈥�

It鈥檚 not clear how Conservative Leader Pierre Poilievre would get along with either presidential candidate.

Ivan Ivanov, an assistant professor at the University of Ottawa, said Poilievre 鈥渋s a professional communicator.鈥� The expert in public relations and crisis management said the Conservative leader can be combative 鈥� which could hurt or help the bilateral relationship 鈥� but it plays well among Canadian voters.

During President Joe Biden鈥檚 state visit to Canada last year he met with Poilievre and they discussed Canadian exemptions to Buy America rules, national defence interests and other issues. A photo shared on Poilievre鈥檚 social media shows the leaders shaking hands.

However, Ettinger said he doesn鈥檛 think we can 鈥済lean much about how he personally will interact with other leaders on the international stage.鈥�

鈥淗e鈥檚 a complete cipher.鈥�

Poilievre鈥檚 promises share some insight. He pledged to match American tariffs on Chinese-produced electric vehicles a few weeks before the Liberal government took action this summer and promised to push Americans on the longstanding softwood lumber dispute.

Poilievre has also been known to use slogans in the Republican lexicon. For example, Poilievre said he will 鈥渞eplace woke culture with warrior culture鈥� in the military and that 鈥渂iological males鈥� should not be in women鈥檚 sports and change rooms 鈥� both talking points were included in multiple speeches at the recent Republican National Convention.

But that doesn鈥檛 necessarily make him the better match for Trump, Dawson said.

鈥淲e might think that a Poilievre-Trump pairing would be better because he鈥檚 got a more ideological fit,鈥� Dawson said.

鈥淏ut we know that Trump is not a traditional Republican at all.鈥�