But to your point, the first substantive link off the official Prop. 30 summary page (http://voterguide.sos.ca.gov/propositions/30/analysis.htm) makes clear in several places that the increases will take effect starting Jan. 1, 2012. ("Because the rate increase would apply as of January 1, 2012, affected taxpayers likely would have to make larger payments in the coming months to account for the full-year effect of the rate increase.")
If the OP was worried about taxes, he should feel lucky that 38 failed ;-).
I definitely agree with this (-:
You're right, in that a reasonably informed voter should have known the nature of the proposition. Unfortunately, due to the broken initiative process, those weighing the options tend not to be sufficiently informed. In my opinion (though not that of the US Supreme Court, see Calder v Bull), such ex-post-facto tax laws should be as prohibited as similar laws are in criminal circumstances.
It sounds like you're looking for reasons to become more conservative.
It has been quite clear to all residents that the state of California has been in trouble for a couple of years now. Teachers being let go en masse, school districts seeing cuts in state funds, and state services from campsites to the DMV being cut.
The text of the Prop. 30 tax increase was originally finalized in March 2012, was sponsored by the Governor, and received a big push from him. The original text of what became Prop. 30 was developed by the Governor in 2011 (http://ag.ca.gov/cms_attachments/initiatives/pdfs/i1035_11-0...).
If you're significantly affected by this increase in marginal tax rates (an extra 1% for individuals over $250K/couples over $500K, up to 3% for individuals over $500K/couples over $1M), you should be aware of these issues, or be paying someone who is.