In a talk at Notre Dame, Denver Archbishop Charles Chaput was asked why Catholics were so divided over the issue of whether or not to deny communion to pro-choice politicians. His response:
It would be more accurate to say that Chaput and very few other bishops interpret Canon 915 in such a way as to suggest that such denial of communion should be the norm, while the vast majority of bishops disagree.
The reasons for their disagreement is obvious: It is lousy theology. There are many reasons why someone might not support a certain piece of legislation that would restrict or criminalize abortion.