As noted, this is a very partial list, and excludes the kinds of questions that all voters ask, regardless of beliefs. This list is not meant to be an argument for any candidate or party, but rather a representation of several key issues of interest to Catholics.
It is interesting to note that Barack Obama won the Catholic vote in 2008, in spite of protestations by several bishops that his platform did not well represent the issues they highlight in their quadrennial document Faithful Citizenship. This datum suggests that, like many voters, Catholics tend to respond to economic conditions more than any other. And in truth, since many social issues are tied to the economy (jobs, poverty, health care, education, abortion, to name a few), it is not surprising that a perception about a candidate's ability to steer the economy well remains deeply significant to Catholic voters.