PRINCETON, NJ -- Barack Obama has, for the moment, re-established a double-digit lead over Hillary Clinton in national Democratic voters' nomination preferences in Gallup Poll Daily tracking, 52% to 42%.

Since just after the North Carolina and Indiana primaries, Obama has led Clinton nearly every day, including a stretch of double-digit leads in the May 18-22 Gallup Poll Daily tracking releases. Since then, his advantage had been slightly less, at five to eight percentage points, but is back to a 10-point lead in the latest data. (To view the complete trend since Jan. 3, 2008, click here.)

Just three primary contests remain, and news reports suggest that the dispute over the Michigan and Florida convention delegations will not be resolved in the best possible way for the Clinton campaign. The Democratic National Committee will meet this weekend and likely allow either half those states' delegates to attend, or the full delegations to attend, but with each member given half a vote. Thus, it is a near certainty that Obama will have clinched enough delegates to win the nomination under the current rules, and Clinton's only hope of winning the nomination may reside in lawsuits or a convention floor fight.

In a bit of a change from recent days, Obama and Clinton are both running similarly versus John McCain in the general election. Clinton had fared better in recent trial heats than Obama, but the latest update shows both races as statistical ties -- Clinton 47%, McCain 45% and Obama 46%, McCain 45%. -- 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 25 and 27-28, 2008. For results based on this sample of 1,279 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 23-25 and 27-28, 2008. For results based on this sample of 4,365 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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