This push to legalize sports betting has sparked hope for faster legalization of online casinos in California. However, recent years have seen significant developments, particularly with sports betting. The state potentially leaves substantial revenue untapped by maintaining a ban on online casinos. But despite representing the largest potential market in America, online casinos and other forms of online gambling are not legal in California. So one can only imagine the potential tax revenues the Golden State can generate from legal gambling. Home to more than 39 million people, California is the most populated state in the US.