It is a category devoid of any meaning or worth.
The only relevant category is regular mass going versus not-regular mass going. Pollsters refuse to use those, by and large, because they know that people who were baptized "catholic" but haven't darkened the door step of a Catholic Church in half a century will still self identify as "Catholic" for polling purposes, and that serves their agenda.
Then ask them to quit polling or mentioning the Jewish vote as well, or Protestant, or Evangelical or anything related to religious categories.
For most of us those categories work, it helps to know what the Catholic vote is, not just the most devoted and pure Catholics as you measure them, but Catholics as designated by the Pope, and his official count that he issues as fact.
At least the Catholic vote consists all of members of the same exact church, not like the broad “Protestant” which covers all types of disparate churches and such, including the black militant churches.