Trade and immigration restrictions won't bring back the Rust Belt. What might? Consider the transformation of the Sun Belt.
The South used to be the nation's Rust Belt. The devastation of the Civil War rightly gets the headlines, but the devastation didn't end when Sherman marched out of Atlanta. Industrial agriculture had the same impact on the Southern economy that automation and outsourcing have had on the manufacturing economy of the Midwest. In the late 19th century, much of the South consisted of an increasingly uncompetitive agricultural economy and woefully inadequate infrastructure. Those who could leave for other parts of the country, like factory jobs in what we now call the Rust Belt, did.