United States presidential candidate John McCain now retains a lead over Barack Obama in several polls conducted in the past few days. Both Zogby International and Rasmussen Reports have McCain with a slight, but not statistically significant lead. The most recent Gallup tracking poll has McCain with a statistical lead of 5.0 percent. The Day to Day Politics Poll Average also has a slight, but not statistically significantly lead of 0.4% for McCain. Obama had a 6.0 percent lead in the Day to Day Politics Poll Average after the Democratic National Convention, but now is trailing after the Republican National...