Had a little time today, so just doing some reading.

Trump says that Congress should not interfere with trade negotiations, or he will simply terminate NAFTA.  He says he loves Canada, but is tired of being taken advantage of for so many years.  (If anyone does not believe this to be true, just ask the simple question - why is Canada so terrified of this possibility of NAFTA being terminated?)

Any change in the current situation is a loss for Canada.

The steel/aluminum issue is a bad one for Canada, as they have no facilities for manufacture anymore.  This is probably because of liberal environmental policies.  

Canada is protectionist in lumber, aeronautics, agriculture, banking, telecommunications, etc.  This is what Trudeau calls protecting Canadian workers.  The tariff on autos will add 20-25%, and result in auto companies moving back to the US - along with jobs, of course.  

How is Justine going to spin this politically?

I feel bad for Canadians.  They have had such incompetent leadership.  This didn't have to happen - at least this badly.