If you haven’t checked out Politico’s Arena, a “super blog” where policymakers and opinion shapers debate timely issues, take a few minutes to read Dr. Robert P. Jones’ contribution to the ongoing conversation about Franklin Graham’s controversial remarks about President Obama’s faith. As Dr. Jones points out, Graham, who declared that he did not know if Obama was a Christian, is the latest in a string of conservative and Republican leaders who have questioned the president’s faith. Their inflammatory comments point to a larger challenge for Obama:

Fewer than four-in-10 Americans (38 percent) can correctly identify Obama’s religion as Christian, and four-in-10 say they do not know what his religious beliefs are. About one-in-five (18 percent) Americans continue to wrongly categorize Obama as a Muslim, a misperception fueled by comments like Graham’s, who declared that the Muslim world would consider Obama a “son of Islam.” Perhaps a bigger problem is that a majority of Americans say President Obama’s religion is somewhat different (35 percent) or very different (16 percent) from their own.

Why does this matter? Fully two-thirds of voters (including majorities of Republicans, Democrats and Independents) say that it’s important for a president to have strong religious beliefs, and a solid one-in-five (19 percent) say they would be less likely to vote for a candidate whose beliefs were different from their own. The correlation between perceptions of Obama’s religion and Obama’s favorability, which is nearly linear, bears this out. For example, in PRRI’s 2010 American Values Survey, among those who say Obama’s religion is very different from their own, Obama’s favorability was just 20 percent, compared to 52 percent in the general public.

To read the whole piece, head over to Politico’s Arena blog.