... the votes Trump will most definitely get from the Rust Belt.
... at least half of them would vote for Bernie.
... I firmly believe the Rust Belt vote would be at least split ...
My point is you admit you have no idea why minorities vote the way you do, yet you base your analysis on your absolute confidence in how these other groups will vote.
All you know is who you will or won't vote for, and what reasons you tell yourself for those choices. You are completely unable to see someone else's point of view long enough to understand their choices.