NAFTA - thanks to Clinton, Dole and Bush.
Perot warned us of what was to come and we ignored him. Trump is warning us of what is to come. Will we ignore him, too?
And both of them being nutcases has nothing to do with it. One spoke the truth and the other is speaking the truth.
The biggest impact of NAFTA is that it prevented any of the nations from nationalizing their energy resources. This was particularly important for western Canada, which was decimated in the 1980s when the economy collapsed after the Trudeau government nationalized the entire energy sector. It's no coincidence that Saudi Arabia was surpassed by both Mexico and Canada as the largest foreign sources of crude oil for the U.S. by 2000. This never would have happened before NAFTA.