My thoughts exactly. Once McClintock reminded me, I slapped my forehead. He said in the interview that the voters defeated a new law at the ballot box a few years ago. I'm sorry to say I don't remember which one.
There were a couple of "Fair Insurance Responsibility" laws passed in 1999 which the trial attorneys supported and the insurance companies fought. The insurance companies were able to qualify two referenda (Propositions 30 & 31) and overturn the laws.
There was also a major threat of a referendum when the California legislature passed a bill in 1999 to effectively outlaw big-box stores like Wal-Mart and Costco. Costco inundated Gray Davis with hundreds of thousands of postcards that it collected from customers opposing the bill. Caught between the unions, who hate Costco and Wal-Mart, and the certain threat of a successful referendum (as evidenced by the postcards), Davis ended up vetoing the bill.
The barriers to a referendum are usually too great. There's very little time to circulate the petitions, it's very expensive, and the technical requirements are heavy (e.g., the entire text of the law must be printed with each individual petition, even if the law were to run to hundreds of pages). But it can be done. I have no doubt that it will be done, if necessary, should the Legislature proceed to hike the Car Tax.