John McCain continues to trail Barack Obama in the Gallup daily tracking poll, but the gap between the two is down to three percent.

The national polling lead is a slight dip for Obama, who in the past five days had maintained a 4 percent to 6 percent lead among registered voters. the polls margin of error is +/-2, so it indicates that Obama is still favored in the race.

Again, it's a poll, and it's only September. But the conventional wisdom is that as the economic situation gets worse, Obama's chances for election get better. At the very least, a slight decline in support would seem to indicate that advantage isn't as strong as once believed.

The next potential game-changer in this election comes Friday, when the two debate in Mississippi. The topic there will be foreign policy.