White evangelical Protestants have long been a key part of the GOP coalition. In 2008, 65% of white evangelical Protestant voters identified as Republicans or said they leaned toward the Republican Party, while 28% expressed support for the Democratic Party. By 2010, support for the GOP had increased to 69% among evangelical voters while support for the Democratic Party had declined to 23%. These Republican gains persisted in 2011, with polls showing that 70% of evangelicals favor the GOP compared with 24% who favor the Democratic Party. The 37-point advantage the GOP held in 2008 among evangelical voters has become a 46-point advantage in 2011.


Mormon voters, like evangelicals, are a largely Republican-leaning group. In 2008, nearly seven-in-ten Mormon voters (68%) favored  the GOP. Since then, the number of Mormons saying they lean toward the GOP has increased significantly, bringing the total number who say they identify with or lean toward the Republican Party to 80%. The GOP now holds a 63-point advantage over the Democratic Party among Mormons.


In 2008, white mainline Protestants were evenly divided between the two parties, with 45% identifying as Republican or saying they leaned toward the Republican Party and an equal number identifying with or leaning toward the Democratic Party. By 2010 and 2011, however, the number of mainline Protestants favoring the Republican Party had jumped by six points (to 51%), and Democratic support had dropped by six points (to 39%). White mainline Protestants are now 12 points more likely to express support for the GOP than for the Democratic Party.


White non-Hispanic Catholics polled over the course of 2008 expressed significantly more support for the Democratic Party than for the GOP. In fact, the Democrats enjoyed an eight-point advantage over the GOP in Pew Research Center polling conducted in 2008, with nearly half of white Catholics (49%) expressing support for the Democratic Party and about four-in-ten (41%) identifying as Republican or saying they lean toward the GOP. Today, the tables have turned; the percentage of white Catholics identifying with the Democratic Party has declined significantly and the number leaning toward the GOP has grown. Combining partisans and partisan-leaners, the GOP now enjoys a seven-point advantage among white Catholics.


Republicans have also seen gains among Jewish voters, who have long been strong supporters of the Democratic Party. In 2008, 72% of Jews identified themselves as Democrats or said they leaned toward the Democratic Party, and Democrats held a 52-point advantage among this group. In 2011, the Democratic advantage among Jews has shrunk to 36 points, with 29% of the Jewish population aligning with the GOP. While the majority of Jews are still Democrats or lean toward the Democratic Party, Democrats’ dominance among this group has weakened since the last presidential election. In fact, Jews are the only religious group analyzed in which the percentage who identify themselves as Republican (as opposed to leaning toward the GOP) has risen significantly.


By contrast with other religious groups, changes in the partisanship of religiously unaffiliated voters have been more modest. In 2008, 64% of religiously unaffiliated voters identified with or leaned toward the Democratic Party; in 2011, this figure stands at 61%. There has been little change in the partisanship of black Protestants, another core Democratic constituency.