I agree, Cozie. Technically the Constitution doesn't provide for secession. For a 'legal' secession an amendment would have to be made to the Constitution to allow for it and provide a 'pathway'. This would require 2/3 of the states approval vote and would be very unlikely to happen for two reasons; Firstly, California is understood to be an economic 'necessity' to the US economy. You'd probably have some 'red' states approve it thinking "Fuck you California, you commie pinkos. Who needs YOU?" but I think 'cooler' heads would prevail. The second reason is that when an amendment is proposed, it automatically opens everything IN the constitution to revision. So you'd have people with agendas appending things to restrict our freedoms or change our laws by changing or proposing other amendments to the Constitution.
Which begs the question, what would Trump actually do if CA suddenly said 'We are no longer part of the US' and moved to close ports and borders using the CA Natl Guard? If federal offices and facilities were ordered to close and GTFO of CA? Would he actually order the military in CA to move against us? Scary thought!
Personally I'd like to see the 'United Republic of the Pacific' comprising CA, Oregon, Washington, and Hawaii. Now THAT would be paradise!