The Catholic vote is what it is, what it has always been, and what it will remain to be in the future.
There is plenty, unless you are intent on staying on message. Why don't you begin by addressing Bill Donohue's point below:
"...there is a serious question whether non-practicing Catholics should be considered Catholic. By way of analogy, if someone tells a pollster that he is a vegetarian, but has long since abandoned a veggie-only diet, would it make empirical sense to count him as a vegetarian? Self-identity is an interesting psychological concept, but it is not necessarily an accurate reflection of a person’s biography."