I had perhaps foolishly entertained the notion that the #Calexit "independent California" movement might be a serious attempt to declare independence from the United States, and I described the hurdles facing a prospective ballot measure. I've now read the actual proposal, and it's entirely unserious, in a number of different ways, worth noting now that the proposal has been approved for circulation. I would read the text of the proposal first, which is shockingly minimalist. It does two things: amends the California Constitution to eliminate the provisions that California is "inseparable" from the United States and that the Constitution is the "supreme law of the land"; and calls for a "plebiscite questions" in 2019 on independence, which, if favorable, would require the governor to apply to the United Nations.
There a lot--a lot--of problems with this proposal. To name a few:
First, the initiative repeals the constitutional provision that "The state of California is an inseparable part of the United States of America, and the United States Constitution is the supreme law of the law." Never mind the dozens of other places in the California Constitution that refer to the United States of America or the United States Constitution--for instance, requiring state legislators to be citizens of the United States (Article IV, section 2) and the Governor (Article 5, section 2).
Second, the initiative makes no attempt to call for a constitutional convention, which would be necessary for this and other reasons--for instance, no need to elect United States presidential electors, senators, and representatives.
These problems alone indicate that #CalExit is not a serious independence proposal. Proponents claim this would be a "first step," but it is hardly any step at all--except, I suppose, an opportunity for earned media to treat the movement seriously despite the lack of legal impact of the movement.
Third, the initiative provides, via statute, for a "plebiscite question" given to the voters with the condition that at least 50% of registered voters participate for it to pass. California Constitution Article II, Section 10(a) provides no minimum participatory threshold for an initiative to take effect.
Fourth, the initiative provides, via statute, for a "plebiscite question" given to the voters with the condition that at least 55% vote "Yes." California Constitution Article II, Section 10(a) requires only a "majority" to pass initiative statutes.
Fifth, ballot initiatives are now to occur on the first Tuesday following the first Monday in even-numbered years, Cal. Election Code 9016. The initiative provides for elections in March of odd-numbered years and does not amend or refer to 9016 to account for this change. (Indeed, the California legislature recently amended this provision to ensure that major initiatives and referenda would occur in instances with higher voter turnout, March of odd-numbered years being among the lowest of turnout.)
Sixth, the "plebiscite questions" likely exceeds the power of the people of California to behave via initiative. California courts regularly conclude that the initiative power, even under "the most liberal interpretation," limit the power to the adoption and rejection of "statutes." Such conclusions come from AFL v. Eu and many California state appellate rulings. Declaring that the governor must behave in a certain way--that is, petitioning the United Nations for statehood--is not really a legislative enactment embraced by statute.
Seventh, and relatedly, the people of California may lack the power to direct the Governor to do something. For instance, in Widders v. Furchtenicht (2008), a California appellate court concluded that the initiative power was inappropriate to direct the city council to exercise its "informed judgment" in promulgating laws about housing and retail stores.
It's possible that some would consider the amendment to be a "revision" of the state's constitution, but I highly doubt that removing some largely precatory language--part of which is already redundant of the federal Constitution, anyway--amounts to a revision.
It's also worth noting these problems are not necessarily fatal to the measure appearing on the ballot. California courts in particular are reluctant to engage in pre-enforcement challenges on the merits of a proposed initiative, in the hopes that such questions might be mooted if the initiative fails to get enough signatures or fails at the ballot box.
Some of the problems outlined above might be cured with statutory construction that would give effect to the challenged provisions. Others might simply be notes about the limited nature of this question left for subsequent legal amendments. But they are, I think, serious reasons why the #Calexit proposal is decided unserious.