Gallup Daily: Obama Leads Clinton 51% to 44%

PRINCETON, NJ -- Barack Obama remains the leader in national Democratic voters' nomination preferences, 51% to 44%, over Hillary Clinton, but his lead has fallen below double digits for the first time in six days in Gallup Poll Daily tracking.

Obama has held a statistically significant lead over Clinton for most of the last two weeks, with that lead stretching to as much as 16 percentage points in May 16-18 polling. Obama did not poll as strongly in Gallup's Thursday night polling (May 22); the coming days will reveal whether that is the start of a new trend or a temporary blip. (To view the complete trend since Jan. 3, 2008, click here.)

In recent days, Obama has held a slight advantage over John McCain in registered voters' preferences for the general election. The latest update, based on May 18-22 polling, finds the two tied at 46%.

In contrast, Clinton has a five-point lead over McCain, 49% to 44%.

Recently, Clinton has tended to fare slightly better in trial heats against McCain than Obama has, with the Democratic candidates doing equally well on a few occasions. Obama has not exceeded Clinton's performance versus McCain in Gallup Poll Daily tracking since the April 17-21 tracking period. -- 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 Democratic nomination results are based on combined data from May 20-22, 2008. For results based on this sample of 1,230 Democratic and Democratic-leaning voters, the maximum margin of sampling error is ±3 percentage points.

The general election results are based on combined data from May 18-22, 2008. For results based on this sample of 4,471 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.