For the first time since March, the Democrats have a statistically significant lead on a generic Congressional ballot, according to the latest Gallup poll. The Democrats lead by 6 points.
The Gallup poll shows that the Democrats' gain comes largely from Independent voters shifting towards Democrats. It is unclear what caused the shift, or whether it will last.
Gallup suggests that passage of the financial reform legislation, which most voters favor, could have caused the jump. Perhaps the shift has less to do with the Democrats' performance, than with disarray among Republicans.