Obviously, the neo-fascist real estate mogul has been able to use 'free trade' as a wedge issue to divide the Working Class because the Democrats have sold out the Working Class. It started well before it became the party of the business class under Clinton, Biden, Gore and Lieberman, but workers remember Clinton and NAFTA.
Trump could win as much as 40% of the union vote because many union members hate Clinton, know the Democrats are frauds, and/or are willing to vote for a demagogue out of sheer stupidity. The labor movement has done little, if anything, to educate union members or organize against the corporate democrats who have betrayed unions after every election.
The only hope for the working class is a mass revolt to shut down Trump and Clinton. Short of that, opening the presidential debates to include the Libertarian candidate - who will help drive a wedge in the Trump voter base - and the Green Party's Jill Stein - who will expose the whole system as the sham it is and strike fear into Clinton in a way that Sanders never did. If Trump is elected, blame the Clintons for pushing job-killing trade deals and doing zero for workers.