Plans by PolyMet Mining Corp. to open a copper and nickel mine in Minnesota are putting Governor Mark Dayton on the hot seat and dividing the Democratic Farmer-Labor Party just months before Gov. Dayton faces a reelection campaign in 2014. Green DFLers oppose the project, whereas Iron Range DFL members are among its strongest supporters. Demand for copper and nickel is soaring, and despite U.S. financial support for the Roy Hill Mine in Australia, the PolyMet mine would likely stimulate the local economy.