Pew: Religion and the 2012 South Carolina Republican Primary [View all]
http://www.pewforum.org/Politics-and-Elections/Religion-and-the-2012-South-Carolina-Republican-Primary.aspx
ANALYSIS January 23, 2012
In his South Carolina Republican primary win, Newt Gingrich received strong support from born-again/evangelical Christians and from voters who said that it is important to them that a candidate shares their religious beliefs. Gingrich also won a plurality of votes among Protestants (42%); Catholics in the National Election Pool exit poll were more evenly split between Gingrich (37%) and Mitt Romney (29%).
Gingrich was the clear winner among the two-thirds of South Carolina primary voters who described themselves as born-again or evangelical Christians, earning 44% support. Romney (22%) and Rick Santorum (21%) finished far behind Gingrich among evangelical voters, while Ron Paul received 13% support from this group.

Romney fared significantly better among the one-third of South Carolina voters who did not describe themselves as evangelical Christians than he did among evangelicals; 38% of non-evangelicals voted for Romney, compared with 33% who supported Gingrich, 15% who voted for Paul and 10% who backed Santorum.