Been There, Done That
Having a celeb businessman as governor sounds like a great idea until you actually get one. It didn't work our terribly well for Arnold despite him working quite hard to make it a success. (He differs markedly from the other political dabbling Celebrity Apprentice host in that respect -- Donny's apparently got neither the attention span or the sheer application that Arnold has.)
Currently Republicans are a seriously endangered species in California, and for good reason. They bring nothing but chaos and divisiveness in their wake and their promises of fiscal probity are laughable -- they economize so they can feed the loot to their mates. There are signs that somewhat more sensible ones are about but given the current Federal government we're unlikely to embrace a Trump clone unless there's a provable Second Coming.
The answer to the puzzle as to why people want our governor's job so badly that they're prepared to spend huge amounts of money on it is simple. California's economy is one of the largest in the world -- about the same size or slightly larger than France's, I'm told. We are a major country in our own right (too bad we have to carry large swathes of the "Heartland"....).