Nice thought, but there is no right to secede, as the Pledge of Allegiance states “one nation, under God, indivisible.”
The Pledge is not binding on anyone.
While the California Government may not have the right to secede, the people do. If they want to secede, all they have to do is depart out of the Government. Then form a new Government by voluntary association among themselves, and use the jury to dismiss anything the Federal Government tries to do to them. After all, the jury and proclamations in the Preamble to the US Constitution, along with the 6th, 7th, 9th, and 10th Amendments spell this out to the Federal Government, so that the Federal Government can see right in its own documents that they have no authority over the JURY.
This way California will never need to secede. Their new voluntary agreement nation will simply exist and do everything in California, while the formal California State will do nothing except just sit there. If it does nothing, who cares?
If the people of the Southern States had done this before the Civil war, there would have been no Civil War. But, people are ignorant and unthinking. And the Federal Government likes to keep them this way.