A thousand miles south of Granite City, Ill., a gritty steel town on the Mississippi River, West Texas oil rigs have shuddered to a halt. Seven hundred miles north, mines in the Iron Range of Minnesota have been stilled. The drilling rigs, with their deep underground pipes, once consumed much of the steel that Granite City’s blast furnaces could produce, while the mines supplied the raw material. So now, more than 2,000 workers at the mammoth United States Steel plant not far from St. Louis are waiting to see if they will be next. This month, the company warned them it might be forced to idle the plant. Layoffs could begin around Christmas. Granite City may be waiting, but a chill in economic activity is already evident across a broad swath of the nation’s heartland stretching from the Gulf of Mexico to the Canadian border, as prices of commodities […]