Barack Obama slipped back into a modest but statistically significant lead over John McCain in the latest Gallup tracking poll conducted June 26 and June 28-29. Obama leads McCain 47 percent to 42 percent with the margin of error at 2 percent. For more most last week, the two were tied.

Gallup also has a survey out today, conducted June 15-19, saying that the "swing vote" this year - political independents and moderates - currently stands at 23 percent and that unlike 2004, they view both Obama and McCain far more favorable than they did George Bush and John Kerry four years ago.

Among voters who say they are certain to vote for one candidate or another, 42 percent say they back Obama to 35 percent for McCain. Eight percent lean to Obama but say they could change their minds compared to 9 percent for McCain while 6 percent are undecided.