The idea of a guy like Trump "renegotiating NAFTA to make it a Good Deal for the US" is laughable. 
"Trump advocates a 45% tariff on goods imported into the U.S. from China. And he wants to establish new tariffs on Mexican imports... – In short, the U.S. Federal Reserve is largely responsible for U.S. job losses since the late 1990s. Chinese and Vietnamese manufacturers have been able to borrow at low cost to build factories to produce goods to compete in the U.S. 
The Trump solution, however, increases costs. A 45% tariff increase would boost the cost of everything imported from China on a one-for-one basis. Even if you assume an offsetting impact due to other exporters replacing China, we’re talking double-digit percentage price increases. Higher tariffs also harm the efficiency of the global marketplace. Things will no longer be manufactured in the cheapest location."
Trump won't be the president, he's too dumb
http://www.wallstreetdaily.com/2016/03/05/donald-trump-u-s-global-trade/