I don't want to dismiss Rick Santorum's second White House bid out of hand. After all, he appeared to be an also ran in 2012 and then lo and behold he caught fire at the right time and won the Iowa Caucus. Santorum does not give up easily. Grit and determination certainly count for something.
Before proceeding further, I should state, as I have in the past, that I voted for Santorum in the 2012 Massachusetts Primary despite my disagreement with him on social issues.
However, I do think it will be much harder for Santorum to replicate his 2012 success in Iowa by virtue of the presence of 2008 Iowa caucus winner Mike Huckabee. Sure Santorum is a Catholic while Huckabee is an Evangelical, but their social conservative constituency is fairly similar. These socially conservative could also consider the likes of Ben Carson, Rick Perry, Ted Cruz and let's not forget the Iowa born Scott Walker.