Save the word "treason" for actual treason and not for a single individual's delusion.
This is not just one individual. La Raza and the groups that desire to reclaim the states lost in the war with Mexico - to be named Atzlan.
This is a modern day group some of whom are similar to The Weather Underground with respect to methods. The FBI infiltrators back then talked about Ayer’s group discussing the need to kill 25 million people who might not be able to be re-educated.
I have read that some of the members(cartel and gangs) of the Calexit group have suggested that they could just starting killing lots of people of European descent so that they would leave California, if they are not successful in seceding. Governor Brown I read, is also supporting the idea of secession.
The movement to form the 51st state from Northern areas of California is following a legal path to that end, and hence there is impetus on the Calexit group to move fast before that can happen.