PRINCETON, NJ -- The latest Gallup Poll Daily tracking update, based on Sept. 26-28 polling, shows Barack Obama with a 50% to 42% lead over John McCain, unchanged from the prior report.

The trend on the presidential horserace showed Obama building momentum heading into Friday's debate, moving from a tie earlier in the week to a five percentage point Obama advantage through Friday interviewing (most of which was conducted before the debate took place). The debate apparently has done nothing to halt or reverse that momentum. Today's report includes two full days of interviewing following Friday night's debate, both of which show Obama with a healthy advantage over McCain. Tuesday's report will provide the first fully post-debate three-day rolling average of voter preferences in the presidential election.

A USA Today/Gallup poll conducted on Saturday showed that Americans who saw the debate were more likely to say that Obama did a better job than McCain.

Obama's 50% level of support matches his high for the campaign, and his eight-point lead is just one percentage point below his largest, achieved after his international trip in late July. (To view the complete trend since March 7, 2008, click here.)

The national political focus remains largely on the government plan to help rid financial institutions of the bad loans weighing down the economy, a plan for which both McCain and Obama have expressed support. The next major event on the presidential election calendar is Thursday's debate between vice presidential candidates Joe Biden and Sarah Palin. -- Jeff Jones

(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. 26-28, 2008. For results based on this sample of 2,732 registered voters, the maximum margin of sampling error is ±2 percentage points.

Interviews are conducted with respondents on landline 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.

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