The Trump administration on Tuesday exempted most of southeast Wisconsin from the latest federal limits on lung-damaging smog pollution, delivering a political victory to Gov. Scott Walker as he makes a new Foxconn Technology Group factory the centerpiece of his re-election campaign. By dramatically reducing the size of the areas required to crack down on smog, Trump EPA Administrator Scott Pruitt overruled the agency’s career staff, a move that will save Foxconn from having to make expensive improvements as it builds a sprawling new electronics plant in Racine County, just north of the Illinois border in an area with some of the state’s dirtiest air.