I'm not talking about the primaries. I agree that Trump's support may not materialize at the primaries, which is what the article suggests.
As for the general, I think Hillary will perform worse than the other Democrats in the rust belt states, and I believe a hard-liner on immigration enforcement will perform better than recent Republicans in this states. Combine this factors and a Trump or Cruz could very well win OH, PA, and perhaps Michigan, which could very well decide the election.