When large dogs eliminate, they eliminate a lot more than small dogs. More goes in and more comes out of large breeds. Which is something to keep in mind if your dog will live inside - especially if you live in a high rise apartment and he will have to be litter box trained (there is always going to be more to clean up).
Dogs have been selectively bred for thousands of years, sometimes by inbreeding dogs from the same ancestral lines, sometimes by mixing dogs from very different lines. The process continues today, resulting in a widening in appearance without speciation, "from the Chihuahua to the Great Dane."
Before you say that the person in California could find another dog closer to home, what if the New Jersey breeder is one of the few people in the country breeding that particular breed? In many cases we are talking about breeds that may only register a few litters per year. That’s why this kind of legislation is so dangerous. In some cases it could literally cause the extinction of breeds. Breeders give up breeding rather than face these kinds of legislative problems.
You do not have to have own a large house to own a large dog (although a tiny apartment is not going to be big enough for one of the giant breeds). If you can take him outside for a good hour of two of exercise every day... a large dog can live in a small house or apartment just fine.