What if you vote for your rational self-interest? This tax applies to income greater than $2 million per year. Let's assume everyone whose tax base will increase will vote against, everyone whose tax base will not increase will vote for. A popular ballot cast this way would pass by a wide margin.
In reality, some people will probably leave, and the rest will likely avoid the increase by receiving the income via lower-rate methods. It seems likely that CA is past the peak of the Laffer curve, and will lose tax revenue.[2]