PRINCETON, NJ -- Gallup Poll Daily tracking finds Barack Obama the choice of 52% of Democratic voters nationwide, while 43% prefer Hillary Clinton.
Democratic voters in South Dakota and Montana will cast the final primary votes today. Obama has won a majority of the pledged delegates, but still needs some superdelegate support in the coming days to clinch the nomination. There is some speculation that enough superdelegates will publicly endorse Obama within the next 24 hours to put him over the top.
Clinton's only hope beyond a floor fight at the convention is to get the vast majority of superdelegates to back her. She is attempting to persuade them by arguing she has won more total votes in the primaries and caucuses than Obama has. This is a matter of some dispute, as different estimates have Obama or Clinton as the leader depending on assumptions about which states are included and how to count caucus results in states that do not report overall candidate support totals.
One other measure that could sway superdelegates is national support for the candidates. Gallup Poll Daily tracking data, involving interviews with random samples of Democrats nationwide, has shown that Obama has consistently held leads close to double-digits in recent weeks. If there were a national primary today to select the Democrats' nominee, Obama would almost certainly prevail.
Another argument the Clinton campaign is using to persuade superdelegates is that she would be the stronger candidate versus Republican John McCain in the fall election. While Gallup's tracking of registered voters' general election preferences has supported this claim at times, presently the two Democrats are both locked in statistical dead heats with McCain, with Clinton up by one percentage point (46% to 45%) and Obama down by one point (46% to 45%). -- Jeff Jones
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 31-June 2, 2008. For results based on this sample of 1,273 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 28-29 and May 31-June 2, 2008. For results based on this sample of 4,397 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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