The key to understanding Canada’s border problems

The safe third country agreement, in place since 2004, is at the heart of every story you hear about Canada's border security. It impacts everything from where asylum seekers cross, what happens to these people when they do cross, and the message that sends to the world at large - and to Donald Trump in particular. The agreement was a small piece of a larger negotiation when it began, now it's shaping up to be a major factor in Canadian immigration policy. Maclean's reporter Aaron Hutchins takes us to Roxham Road in Quebec, the so-called loophole in the system.