America’s factory towns, once solidly blue, are now GOP havens

The Republican Party has become the party of blue-collar America. After the 1992 election, 15 of the 20 most manufacturing-intensive congressional districts in the U.S. were represented by Democrats. Today, all 20 are held by Republicans. The shift of manufacturing from a Democratic stronghold to a Republican one is a major force remaking the two parties. It helps explain Donald Trump's political success, the rise of Republican protectionism and the nation's polarized politics. It will help shape this year's midterm elections.