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.)

Survey Methods

For the Gallup Poll Daily tracking survey, Gallup is interviewing no fewer than 1,000 U.S. adults nationwide each day during 2008.

The general-election results are based on combined data from Sept. 30-Oct 2, 2008. For results based on this sample of 2,728 registered voters, the maximum margin of sampling error is ±2 percentage points.

Interviews are conducted with respondents on land-line telephones (for respondents with a land-line telephone) and cellular phones (for respondents who are cell-phone only).

In addition to sampling error, question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of public opinion polls.