PRINCETON, NJ -- Barack Obama maintains a statistically significant lead over John McCain among likely voters interviewed Tuesday through Thursday as part of the Gallup Poll Daily tracking program, with a 51% to 44% margin using an "expanded" model that takes into account possibly greater turnout by new or infrequent voters, and a 50% to 45% margin using the "traditional" model Gallup has employed in past elections.
These results are based on Oct. 21-23 polling. The precise numbers vary slightly from day to day, as would be expected given normal sampling considerations and the high-visibility campaign currents that are swirling around voters in the closing days of the campaign. Obama's share of the vote has been within a very narrow range of 49% to 51% among the traditional likely voter group over the last two weeks, and within a 50% to 53% range among the expanded likely voter group. There has been only slightly more fluidity in McCain's share, ranging from 44% to 47% among traditional likely voters, and 42% to 46% among the expanded group. These slight shifts in estimates of each candidate's share are minimal. Nothing so far represents a major change in the structure of the race, and the big picture conclusion is that Obama is maintaining his lead over McCain with less than two weeks to go before Election Day.
Obama's lead among registered voters is at eight percentage points, 50% to 42%. (To view the complete trend since March 7, 2008, click here.) -- Frank Newport
(Click here to see how the race currently breaks down by demographic subgroup.)
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 Oct. 21-23, 2008. For results based on this sample of 2,787 registered voters, the maximum margin of sampling error is ±2 percentage points.
For results based on the sample of 2,406 "traditional" likely voters (based on the model taking into account current voting intentions and self-reported past voting behavior), the maximum margin of sampling error is ±3 percentage points. The traditional likely voter model assumes a turnout of 60% of national adults. The likely voter sample is weighted to match this assumption, so the weighted sample size is 1,822.
For results based on the sample of 2,365 "expanded" likely voters (based on the model taking into account current voting intentions only), the maximum margin of sampling error is ±2 percentage points. The expanded likely voter model does not make any assumptions about turnout level.
Interviews are conducted with respondents on landline telephones (for respondents with a landline 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.