First of all, it's not the major concern. The major concern is that we have to protect the integrity of our system, and we have 800,000 people waiting to get here legally.
The answer to that is that if you announce a regularization and there are a number of countries with whom you don't have visas, then pretty soon Canada becomes very attractive as a place for people to flood into in the hope there will be a regularization in the future, meaning you have all kinds of people here whose security status is unknown. You don't know if they're involved with criminality, and because we have such a large open border with the Americans, it could prove to be an issue.
They're our largest trading partner; we do 84% of all our trade with them. We don't need more barriers between Canada and the United States in a way that hurts our prosperity.