What's Behind Obama's "Committed Christian" Mailer?

The Obama camp has a new South Carolina mailer touting him as a "committed Christian" who has been "called to Christ." (TPM Election Central has the full image.)

As Greg Sargent notes, the Obama-Muslim smear has been pushed around heavily in South Carolina, mostly via email. But it's unclear whether the Obama camp is making a pro-active step to ensure this doesn't cost him votes, or whether the campaign has data showing that the smear had an impact in earlier contests.

Obama spokesman Bill Burton seemed to indicate the former in an email to the Huffington Post:

"No matter how the smears come at us, we have to be forceful in defending the truth about Obama's record and his life. Voters don't know Obama as well as they know the Clintons so we have to spend more time making sure that people have accurate information about his biography."

In the last few weeks, Jewish leaders and members of Congress have released letters defending Obama. Of course, thanks to the inexplicable fact that exit pollsters collect religious information from Republicans but not Democrats, we can't tell how Obama has performed among Jewish voters (or among evangelicals, born-agains, etc.).