Republican candidate, Rick Santorum, has already won the support of the evengelical Republican base.
Now, according to opinion polls, he is tipped to win Mitt Romney's home state, Michigan.
A Santorum win in Michigan may lead some Republicans to search for a new candidate, as some worry the former Pennsylvania senator's strong religious views could make him unelectable.
CNN's Jonathan Mann profiles the Republican candidate and what he has said about his faith.
