I agree that Biden was chosen partly because he’s Catholic. Whether that will have any effect remains to be seen.
Kerry claimed to be Catholic also... see where it go him. If I remember right, Bush won the Catholic vote.
Frankly, I don’t really think there is a Catholic vote per se. Those who are active in the faith will always vote pro life because of their faith and those who aren’t active in their faith will vote without even considering religion.
I think the same goes for non-Catholics.