Most of these voters are expecting Trump to bring back all the factory jobs which no longer exist because of automation. Of course there will still be resentment and racial politics but people still do expect results.
I know Trump can't bring all jobs back, but what if he breaks all the promises that he can keep and privatizes New Deal and Great Society programs he promised not to? How will that affect the outcome in the Rust Belt? Trump said he would stop TPP, and he can. What if he doesn't stop TPP? He can veto Paul Ryan's phaseout of New Deal and Great Society programs. What if he doesn't?