Such as? Mail order isn't an option. California doesn't have the Indian cigarette industry that New York has. And yes border runs to smuggle cartons in will increase but the overall effect will be a DECREASE in demand.
Plenty of Indian reservations in this state. Online services that will accommodate duty free purchases. Southern California ports of entry from Mexico, even though only 1 carton at a time if bought Duty-Free, or 4 cartons at $4 Duty.
There will be even more choices and black market expansion due to these taxes.
Demand falloff is rarely about price when you're talking about tobacco.