In what's almost certainly a first in the lengthy history of bilateral relations between the countries, Canada's summer-jobs program has become the object of criticism from America's right wing.
The reason is abortion.
A former Trump White House adviser, several news organizations and the president's favourite Fox News morning show have all dumped on Prime Minister Justin Trudeau's explanation for why pro-life groups should be excluded from $220-million in federal jobs grants.
The prime minister's suggestion that pro-life groups were out of line with Canadian society triggered criticism in the country next door – where abortion remains a subject of mainstream political debate and is a central issue in the struggle for control of the U.S. Supreme Court.
"This man is reprehensible," tweeted former White House staffer Sebastian Gorka.
It's not the first time Trudeau has landed on the radar of the American right.
While he's drawn fawning profiles in mainstream magazines and polls have suggested he's relatively well-liked in the U.S., there are three cases now where he's drawn conservative ire down south, after his praiseful eulogizing of Fidel Castro and the multimillion-dollar legal settlement with Omar Khadr.
There were even a few boos at a Republican rally in Florida recently when President Donald Trump mentioned Trudeau's name – though the president interjected quickly to silence them: "No, I like him," Trump said. "Nice guy. Good guy."
The latest controversy involves a new Canadian policy – when applying for federal grants for student jobs, organizations are now required to sign a form attesting that neither their core mission, nor the job being funded, opposes human rights, including reproductive rights.
Pro-life activists are suing the federal government over it.
The abortion controversy produced a segment Monday on the morning show "Fox and Friends".
Host Brian Kilmeade said: "What message is he trying to send to us, maybe?" Co-host Rachel Campos-Duffy added: "What happens in Canada often comes down to us. This is an effort to silence pro-lifers. ... This is a sign of intolerance. If you have a pro-life view you're not welcome to share it or else you're kicked out of this program."
They invited the head of largest American annual pro-life march onto the air to discuss it. Jeanne Mancini, whose annual March for Life is later this week, said she hoped to invite the prime minister to attend the rally.
"Because he will see who's really out of touch with mainstream America," Mancini said. "We've lost over 60 million Americans to abortion. To the prime minister, I would just really want to talk to him."
Trudeau discussed the controversy in an interview Monday with The Canadian Press.
He said he's a Catholic who has long had to reconcile his religious beliefs with his responsibilities as a political leader and he said the latter demands that he defend people's rights.
In this case, he said that means a woman's right to choose trumps the right to a federal grant.
"An organization that has as its stated goal to remove rights from Canadians, to remove the right that women have fought for to determine what happens to their own bodies, is not in line with where the charter (of Rights) is or where the government of Canada is," Trudeau said Monday.
"Certainly there is no obligation by the government of Canada to fund organizations that are determined to remove rights that have been so long fought for by women."