FILE - In this Jan. 15, 2012, file photo Republican presidential candidate, former Sen. Rick Santorum, R-Pa., bows his head in prayer as he campaigns at a prayer breakfast in Myrtle Beach, S.C. Across... more 
FILE - In this Jan. 15, 2012, file photo Republican presidential candidate, former Sen. Rick Santorum, R-Pa., bows his head in prayer as he campaigns at a prayer breakfast in Myrtle Beach, S.C. Across all states where Republican primary voters were asked their religion in exit polls, Mitt Romney, a Mormon, trounced Santorum among Catholics, with an average margin of victory above 20 percentage points. Even in Southern states, where Romney has struggled, Catholics broke his way. Sunday, March 18, overwhelmingly Catholic Puerto Rico is holding its primary. (AP Photo/Charles Dharapak, File) less 
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Associated Press | Photo By Charles Dharapak, File
Sun, Mar 18, 2012 10:18 AM EDT