Donald Trump on Saturday raised questions about Republican presidential challenger Ben Carson's faith with recent surveys showing the retired pediatric neurosurgeon leading among voters in Iowa and Wisconsin. (snip) The Washington Post reports. "And, look, I don't have to say it, I'm Presbyterian. "Can you believe it? Nobody believes I'm Presbyterian," the billionaire developer added. "I'm Presbyterian. I'm Presbyterian. "I'm Presbyterian. Boy, that's down the middle of the road folks, in all fairness," he said. "I mean, Seventh-day Adventist, I don't know about. I just don't know about."