Background: an upcoming ballot initiative in California, Proposition 22, contains as part of its text the condition that the law it brings into effect can only be amended by a 7/8 legislative majority. As an article in Bloomberg explains:
The long-term implications of Proposition 22 are profound, advocates say, because of strict—and by their account, unprecedented—lock-in measures: If approved by voters, the measure could only be amended with a 7/8 majority of state legislators. “In practical terms, this means there will likely be enough votes to permanently prevent amendments,” reads the report. Any future amendments deemed inconsistent with the purpose of the proposition—meaning anything that challenges independent contractor status—will be prohibited, according to the researcher’s interpretation of the measure.
This measure appears to make it unrealistic for this proposition to ever be modified or repealed, and I am wondering whether it is legal for a California law to entrench itself in such a way. Specific related questions are:
Can the proposition be repealed by a simple majority of California voters through a future ballot initiative?
Can the proposition be repealed by a 2/3 legislative majority who would legislate its repeal through a change to the California state constitution? (Such changes can be made by a 2/3 majority, to my understanding.)
If the answer to 2 is "yes", doesn't that mean that the 7/8 majority restriction is legally meaningless and that the clause with that language should not have been allowed on the ballot by the California state official who is in charge of such things (the Secretary of State, I'm guessing)?
Is there anything special about the number 7/8? That is, can a future ballot initiative include a similar condition in which the number 7/8 is replaced by 99/100? Or by an absolute prohibition on the law it institutes ever being repealed by the legislature?
Does the US Constitution or other US federal laws have anything of relevance to say about the validity of such self-entrenching legislation?