Canada had a huge advantage in labor costs when the CDN$ was 70 cents and health care costs were low to non existent. Now, with the currencies virtually at par, manufacturers are just as well off to produce goods in the US. Canada has an advantage in some agricultural products but entrenched interests on both sides of the border make trade difficult to impossible in these areas. Ask Canadian consumers of dairy and poultry products and US consumers of beef.
The big advantage that Canada has is in production of energy. Canada is actually exploiting its energy reserves, and selling them south. If the US starts to drill, this advantage will also lessen.
if Obama wins, I’d expect a lot of jobs to flow across the border.