In principle, sure. In positive reality things are not so simple.
Consider the bigger strategic political and military reality. California is run by lunatics, many of them almost certainly CCP puppets. Cali secedes and China moves in, establishing a shitload of military bases into which ballistic missiles are homed. What does anyone think is going to happen. In ten minutes DC is leveled by sub-launched cruisers right off the coast, possibly even from within US waters. They can talk all they want of devolution plans, we are going to be fucked as the chinks launch a massive ICBM attack against every military base in America, hitting relevant territories like Guam, Diego Garcia, and so on in a Tet-style offensive that can now be timed to within seconds, thanks to human tech.
In, say, two years' time they could EASILY move ten to thirty million chinks across the sea, trained for battle, and release those hordes in the same attack. We would be at dire risk, our cities and what remains of our industries reduced to ash in a moment. All those bastards need is a foothold, and CA secession I guaRONtee would provide it. Those pigs would do the honeypot deal for awhile, gather their leverage so that Cali opens its doors with no fedgov to countervail them. The local media would handle public perception, as would the universities and even the public schools so the Californians would be ready to suck China's little asian dick.
That cannot be allowed to happen. The political reality destroys the ideal sufficiently to disallow such a move. This is the great downside of civilization; of super organization. Peaceable people cannot survive in the face of a superorganized society that has conquest on its mind. Human history is rotten with examples of this. Furthermore, greater superorganization trumps the lesser example, all else equal.
This is why we cannot escape "government" as a practical evil. If we remove ourselves from that ghastly, nasty institution, we will eventually get it right back as conquerors steam rolled us into oblivion, namely the filthy human cockroaches we call "Chinese" and "Muslim".
To walk away as fifty states and remain intact and nominally safe from the alien predators, Americans would have to adopt a Spartan culture. That's not going to happen any time in the coming thousand years, so fantasize all you want; secession would be the clusterfuck's clusterfuck. We would be invaded and knocked down one at a time.
I am quite well convinced that the average Johnny has no idea just how tenuous is our position, both politically, economically, and consequently, militarily. Dumbasses think the US armed forces would save the day. They are wrong. If the chinks hit us tet-style, firstly it would not matter whether we struck them back. A carrier battle group needs fuel. In a week or two the jets would have nothing with which to fly, and the escort vessels would need refueling. Having expended their arsenals, replenishment would be required, but there would be none because we got nuked by the chinks. America would be at its end because the idiots of CA will have allowed China a strong foothold in north America and we'd have none because Taiwan and Japan would also be nuked into ash, not to mention all our bases in the region. Remember that this would all happen within seconds of each other, and make no mistake: the CCP has no qualms about sacrificing a couple hundred millions of their own because the Chinese place little value on life. They are of the slave mentality, and the soulless simulacra in charge have zero empathy for those who are to be consumed in the conflagrations to come.
Finally I will say this: if the chinks were to gain such a foothold in Cali, I guaRONtee they would attack. There is no possible way they would pass up such an opportunity for world hegemony. The opportunity to own the entire pacific plus all of north and south America would be a prize too tempting to pass up.
So yeah, go ahead and let the assholes in CA secede and let us see whether I'm full of shit. And even if I am, is this something we want to risk?