Shares of Delta Air Lines, Inc. (NYSE:DAL) are 3.3% lower before the opening bell, following the company's third-quarter earnings report. Not only did the airline giant report quarterly earnings and revenue that missed the mark, it provided a gloomy fourth-quarter revenue guidance on expectations of lower demand before and after the U.S. Presidential Election.Today's dip looks like it will cut into the stock's 26.7% year-to-date lead. After a May 13 four-year peak of $53.86, the shares cooled off in the sum ...