Well, they might if California traded more with the rest of the world than they did with the rest of the US, and staying in the latter's free trade zone meant m

Well, they might if California traded more with the rest of the world than they did with the rest of the US, and staying in the latter's free trade zone meant mandatory tariffs on trade with the former. And if US federal government overrode California state government while having almost zero democratic accountability to Californian voters. I sometimes have a hard time working out what Americans understand by "the EU". Sometimes they seem to think of it as a country like the USA, sometimes they seem to think of it as a free trade zone like NAFTA. It's neither; it's a customs union with supranational governmental aspects designed from the start (for laudible historical reasons) to be heavily insulated from populism. The problem is that it's practically impossible to disentangle "insulated from populism" and "insulated from democracy".