Canada's prime minister faces the biggest political crisis of his career after his top minister resigned. NPR's Steve Inskeep talks to CBC journalist Catherine Cullen about the implications.

MARY LOUISE KELLY, BYLINE: Good morning, Steve. INSKEEP: Who'd you talk to?

CATHERINE CULLEN: Good morning, Steve. INSKEEP: Why is it such a big deal ... she was the original Justin Trudeau liberal before he was prime minister. He recruited her. He brought her on as ...

MARY LOUISE KELLY, BYLINE: Good morning, Steve. INSKEEP: Who'd you talk to ... Trump just had with Canada's prime minister, Justin Trudeau - other foreign leaders he wants to meet from the ...