Yes, California can do this as shown below: Calexit Yes California Independence Campaign, a fringe political group https://www.yahoo.com/news/californians-might-vote-2018-taking-223200544.html, is calling for the nation's largest state to become an independent nation after filing a proposed ballot measure with the attorney general on Monday.
The proposed measure would require a constitutional amendment and therefore require two-thirds majority in both houses or two-thirds of states ratifying. The measure started to gain traction after Donald Trump was announced president on November 9.
