Though both Huckabee and Romney are duly influenced by their respective faiths, they both also try to represent themselves as "the conservative." According to this CNN article, "both men have draped themselves in the mantle of former President Ronald Reagan." Huckabee and Romney have been volleying back and forth, accusing each other of being not-Reagan enough in various (sometime outrageous) manners. For example, Huckabee said of Romney, "When he was against Ronald Reagan's legacy and said he wasn't part of that Bush-Reagan thing, I was a part of that Bush-Reagan thing." Hmm. So it seems that these two Republican candidates are trying to channel Reagan's legacy in the same way as many candidates want to align themselves with the "great Presidents" (JFK, FDR, etc.).
To follow up on Karina's post, Huckabee has been called a "false conservative" (by columnist Robert Novak) and considered to be not as Right as some GOP party members want. So I agree that his religious principles may override his conservative ones. In fact, he has stated that he is a Christian leader and led by faith.