Catholics are those who are members of the Catholic church.
Neither I nor the world of politics and voting data, or the Vatican cares about some guy on the internet creating a personal definition for who is counted as a catholic voter, which has no connection with the facts of church membership or the polling.
And what about those who, through their actions and in actions, have excommunicated themselves. Are they still members? What about those who have become Baptists, Presbyterians, or Evangelicals, are they still members? And what about your objective, what are you trying to accomplish and for who's benefit?
Perhaps you should look beyond the world of politics and polling for things not of this world, but of the next and to the Church for those things you cannot or will not understand.
Peace be with you.