PRINCETON, NJ -- Among major U.S. religious groups, Catholic voters are most closely divided in their presidential voting preferences, with Barack Obama holding a narrow 47% to 43% advantage over John McCain. McCain leads Obama among Protestants (48% to 41%) and Mormons (70% to 23%) while Obama holds the upper hand among Jewish voters (62% to 29%) and those with no religious affiliation (65% to 25%).
These results are based on aggregated Gallup Poll Daily tracking data from June 5-23, with all 14,000+ interviews conducted after Hillary Clinton decided to end her presidential bid. During this time, Obama averaged a 46% to 43% lead over McCain among all registered voters.
Catholics have traditionally been a key swing-voter group, and the 2008 election is proving to be no exception. Since Gallup began tracking general-election voting preferences in early March, the largest advantage either candidate has had among Catholics in any given week has been only five percentage points.
Obama's appeal to minority voters -- including Hispanics -- helps to push him ahead of McCain among Catholics. In these data, roughly one in seven Catholic registered voters report being of Hispanic ethnicity, and they prefer Obama by a 66% to 25% margin. Among non-Hispanic Catholics, McCain has a 46% to 43% advantage.
Obama's overwhelming support among blacks helps him stay within hailing distance of McCain among Protestant voters. Currently, McCain leads Obama by seven points among all Protestants, but white Protestants solidly back McCain (56% to 32%) and nonwhite Protestants overwhelmingly favor Obama (77% to 15%, including the support of more than 9 in 10 black Protestants).
Over the course of the campaign, Obama has come within six points of McCain among all Protestants in Gallup's weekly aggregates (in early June), while McCain has led by as many as 14 points (in late April/early May).
Only about 2% of Americans identify their religious affiliation as the Church of Jesus Christ of Latter-day Saints, or Mormons. They have become a reliably Republican group, and McCain leads Obama by a better than 3-to-1 margin among Mormon voters, 70% to 23%.
Americans of Jewish faith are about as prevalent as Mormons, with roughly 2% of Americans identifying themselves as Jews. They have been a traditionally strong Democratic group, but they have taken on somewhat added significance given questions about Obama's support for the Jewish state of Israel. Obama has taken steps to reassure Americans of his support for Israel. He currently leads McCain by 62% to 29% among U.S. Jewish voters, and has typically held a sizable advantage against McCain among this voting group.
As the general-election campaign has gotten underway, the traditional political/religious alliances already seem to be in place. That includes Mormons overwhelmingly supporting the Republican candidate, Protestants (especially white Protestants) backing the Republican, and Jewish and nonreligious voters favoring the Democrat. Catholics continue to be the primary religious battleground group, and McCain and Obama will do their best to persuade Catholic voters, who have tended to back the winner in presidential elections more often than not. For McCain, that will likely entail an emphasis of his shared moral positions with Catholics (pro-life, anti-homosexual rights). For Obama, his desire to help out the less fortunate will appeal to many Catholic voters.
Results are based on telephone interviews with 14,913 registered voters, aged 18 and older, conducted June 5-23, 2008, as part of Gallup Poll Daily tracking. For results based on the total sample of registered voters, one can say with 95% confidence that the maximum margin of sampling error is ±1 percentage point.
For the sample of 3,480 Catholic registered voters, the maximum margin of sampling error is ±2 percentage points.
For the sample of 8,401 Protestant registered voters, the maximum margin of sampling error is ±1 percentage point.
For the sample of 228 Mormon registered voters, the maximum margin of sampling error is ±7 percentage points.
For the sample of 410 Jewish registered voters, the maximum margin of sampling error is ±5 percentage points.
For the sample of 1,746 registered voters with no religious affiliation, 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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