Wall Street stumbles as discretionary stocks weigh

By Chuck Mikolajczak NEW YORK (Reuters) - Wall Street fell on Tuesday, with each of the major indexes on track for their worst day in over a month, as economic data and weaker than expected auto sales spurred growth concerns. Shares of Ford and General Motors dropped more than 4 percent each after the two major U.S. automakers reported July vehicle sales slightly below expectations. "How long can you stay in a slow growth environment?" said Joe Saluzzi, co-manager of trading at Themis Trading in