For the first time in years, Canada's Liberal Party has overtaken the Conservatives in federal election polling, marking a dramatic reversal just months before voters head to the polls—and U.S. President Donald Trump may be partly to blame.

Canada's ruling Liberals, who a few weeks ago looked certain to lose an election this year, are mounting a major comeback amid the threat of U.S. tariffs and are tied with their rival Conservatives, according to three new polls.