PRINCETON, NJ -- Barack Obama (44%) and John McCain (42%) are essentially tied in presidential vote choice among independents. The two candidates have been closely matched among independents since mid-March, with the advantage switching between McCain and Obama several times.
These results are based on weekly aggregates of Gallup Poll Daily tracking data, with the most recent covering data collected May 5-11.
Since Gallup began compiling the weekly aggregates in mid-March, Obama's support among independents has narrowly ranged between 40% and 45%, and McCain's has ranged between 41% and 48%.
Each candidate wins the vast majority of votes from his own party, with Obama currently holding a 76% to 15% edge over McCain among Democratic registered voters and McCain leading Obama by 84% to 12% among Republican registered voters.
The candidates' own party support has been very stable thus far this year, with Obama's share of the Democratic vote ranging from 73% to 76% since mid-March and McCain's share of the GOP vote between 84% and 87%.
Obama is able to hold his own against McCain despite receiving less support from his fellow partisans because significantly more Americans currently identify as Democrats than as Republicans. In fact, among all registered voters in May 5-11 tracking polling, Obama led McCain by 47% to 43%.
The competition for the independent vote would look quite different if Hillary Clinton somehow emerged as the Democratic nominee. McCain has consistently led Clinton among independents.
But Clinton would also be competitive with McCain among all voters, because she wins a greater share of the Democratic vote versus McCain than Obama does. In the most recent data, 84% of Democrats said they would vote for Clinton versus McCain, compared to the 76% Democratic support Obama receives. Clinton's Democratic support has not fallen below 80% in the weekly aggregates, while Obama has yet to achieve that mark.
McCain holds more of his own party versus Clinton than he does versus Obama, getting 88% of the Republican vote in the recent data, and a range of 86% to 91% since mid-March.
Independents are usually one of the most closely watched swing voter groups each presidential election. However, contrary to expectations, they are not always decisive, in part because turnout among independents is usually lower than it is among those with a political party affiliation.
According to Gallup historical data from prior presidential elections, George W. Bush in 2004, Al Gore in 2000, Jimmy Carter in 1976, and John F. Kennedy in 1960 all won the popular vote despite losing among independents.
It would seem more critical that McCain prevail among independents in order for him to win the November election, given the deficit in Republican identification and voting enthusiasm to the Democrats.
Results are based on telephone interviews with 6,121 registered voters, aged 18 and older, conducted May 5-11, 2008, as part of Gallup Poll Daily tracking. For results based on the total sample of national adults, one can say with 95% confidence that the maximum margin of sampling error is ±1 percentage point.
For results based on the sample of 2,123 registered voters who identify as political independents, the maximum margin of sampling error is ±2 percentage points.
For results based on the sample of 2,194 registered voters who identify as Democrats, the maximum margin of sampling error is ±2 percentage points.
For results based on the sample of 1,758 registered voters who identify as Republicans, the maximum margin of sampling error is ±3 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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