Canadians on Monday are voting to choose a prime minister who will negotiate with President Trump over trade and security, and to navigate their economy through turbulence as businesses freeze spending and hiring.

In their backgrounds and political styles, Canadian election front-runners Mark Carney and Pierre Poilievre are a study in contrasts.

Just as polls were opening in Canada, Donald Trump said on social media that Canadians should “vote for the man” who would make their country part of the U.S.