PRINCETON, NJ -- The latest Gallup Poll Daily tracking update on the presidential election finds John McCain and Barack Obama exactly tied at 45% among registered voters nationwide.

Voter preferences had been fairly evenly divided for the past week, with Obama generally holding a slight advantage of two or three percentage points. This is the first time since Gallup's May 31-June 4 rolling average that Obama does not have at least a slim advantage over McCain. Obama's largest lead to date has been seven points. (To view the complete trend since March 7, 2008, click here.)

Since the changes from Tuesday's results are well within the margin of sampling error, it is unclear at this point if today's results represent a further tightening of the race. The last two individual nights of polling have, however, been more favorable to McCain that what Gallup has shown for most of June. -- Jeff Jones

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 June 22-24, 2008. For results based on this sample of 2,600 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.

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