He was talking about the towns, not the people...
“The truth about these dysfunctional, downscale communities is that they deserve to die. Economically, they are negative assets. Morally, they are indefensible. Forget all your cheap theatrical Bruce Springsteen crap. Forget your sanctimony about struggling Rust Belt factory towns and your conspiracy theories about the wily Orientals stealing our jobs. Forget your goddamned gypsum, and, if he has a problem with that, forget Ed Burke, too. The white American underclass is in thrall to a vicious, selfish culture whose main products are misery and used heroin needles. Donald Trump’s speeches make them feel good. So does OxyContin. What they need isn’t analgesics, literal or political. They need real opportunity, which means that they need real change, which means that they need U-Haul.”
http://www.gopbriefingroom.com/index.php?topic=198401.0
If he had just said "People should move to where the jobs are", he could have saved himself some grief.