That’s a very interesting poll because in the end HRC got 48 percent of the vote, or 2 percentage points more than in this poll, while DT got 46 percent, 11 percent more than in the poll. One explanation could be that undecided, Johnson and Stein voters changed their minds and (mostly) voted for Trump.
I never really get why those types of subsidies should go through the corporate tax. Want to subsidise domestic production? Provide a wage subsidy to companies that employ American workers. The corporate tax code should be as clean and simple as possible.