Today marks full week of Obama leading by significant margin

PRINCETON, NJ — Gallup Poll Daily tracking from Sept. 30-Oct. 2 has Barack Obama leading John McCain by seven percentage points, 49% to 42%.

Obama has held a statistically significant lead over McCain for each of the past seven days, ranging from four to eight points. (To view the complete trend since March 7, 2008, click here.)

Most of the interviewing in today’s three-day rolling average was conducted before Thursday night’s vice presidential debate between Sen. Joe Biden and Gov. Sarah Palin. Saturday’s tracking results will begin to show any impact the heavily watched face-off may have had on voter preferences for president.

Voters’ mindsets about the election in the coming days could also be influenced by the new Labor Department report out today, showing a bigger job loss in September than many analysts had predicted.

The pattern of voter preferences in September — with McCain’s post-Republican convention lead slipping away after the extraordinary Wall Street failures that began in mid-September, and Obama’s lead expanding to as much as eight points — suggests that Obama has benefited from Americans’ intensified economic anxiety during this period. Obama’s advantage on this issue was evident in Gallup’s post-presidential debate polling on Sept. 27, when the poll found Obama receiving much better scores from debate watchers for his performance on the economy than McCain.

The troubling new jobs report will most likely only reinforce, if not deepen, Americans’ economic concern in the coming days. McCain and Obama’s presidential debate this Tuesday could thus prove to be a critical opportunity for Obama to either cement his advantage on the economy, or for McCain to turn it around. — Lydia Saad

(Click here to see how the race currently breaks down by demographic subgroup.)