Obama has a 5-point lead in the Gallup Tracking Poll [in Saturday's release and an 8-point lead in Sunday afternoon's release] and a 6-point lead in the Rasmussen Tracking Poll [in Sunday's release]:

The Rasmussen Reports daily Presidential Tracking Poll for Sunday — including the first day of post-debate polling — is unchanged. Barack Obama once again attracts 50% of the vote while John McCain earns 44%. This six-point advantage matches Obama's biggest lead yet and marks the first time he has held such a lead for two-days running. Obama is now viewed favorably by 57% of voters, McCain by 55%.

As the economic crunch continues, just 11% of Americans now say the nation is heading in the right direction. That's down dramatically from 24% two weeks ago when the failure of Lehman Brothers first brought the Wall Street debacle to the world's attention. Since then, consumer and investor confidence have plummeted and nearly 80% of the nation's adults now believe the economy is getting worse. Adding to the frustration is growing opposition to the proposed rescue plan and doubts about the motives of those promoting it.

UPDATE: Gallup's move from 5% to 8% in Sunday's release indicates that Saturday's polling was 8-10% stronger for Obama than Wednesday's.