If it were just created via simple copy-and-paste, Califournia would have a population of 159 million people, which would be just under half of the current population of the entire country.
If it remained all one state and were not split up, it would certainly turn into a case of the tail wagging the dog. Califournia would be able to split off into its own country with a population and economy rivaling that of the entire remaining 49 states.
Nope, that was accounted for. California is the largest portion of US GDP by state, but it is still only ~15%. The smaller states really add up when there are so many