Here are tables looking at the 5 adult-use cannabis initiatives on November ballots:
Can Legislature amend November marijuana initiatives?
CA: for taxes, only with 2/3 of each House; some amendments need only simple majority
NV: only after 3 years
AZ: only with 3/4 of each House
If recreational marijuana legalization passes, state tax on it will be:
CA: 22.5% + $9.25/oz.
If RECREATIONAL legalization passes, state tax on MEDICAL marijuana will be:
CA: 15% + $9.25/oz. for bud
And some history:
For marijuana initiatives, strongest state taxes correlate with victory
Explanations: https://newrevenue.org/2016/10/06/4951/, http://www.huffingtonpost.com/pat-oglesby/marijuana-taxes-on-2016-b_b_12487528.html