Do the math, condescension.
First, it wouldn;t be just California, but a coalition of blue states. Roughly, it'd be a split in which most blue states leave:
California, Oregon, Hawaii, Washington, New York, New Jersey, Delaware, Connecticut, Rhode Island, Massachusetts Vermont. Given the tax situation in which blue states are over taxed and underrepresented, I'd give odds to being joined by Pennsylvania, Maryland, and New Hampshire, and quite possibly Illinois (Colorado and New Mexico would oppose of course). That's fifteen.
Of the remaining 35 states, I'm pretty certain that deep red states whose population are certain that California and New York are sucking down their tax dollars would vote to send California and New York packing. Not that it is in their interest to do so, but because in their delusion they think it is. Remember these state legislatures are packed with the most looney Republicans due to safe-seat gerrymandering, so they don't give a rats ass anyone not voting in GOP primaries think. Do you really think any of those guys are going to want to face reelection on a "I voted to keep California around" platform? They'd be roasted by the Tea Party and white supremacists!
I'm pretty sure you could get at least 8 of the confederate states to go along, with the exception of Florida and maybe Virginia. That's 23.
So of the Western states, a similar "don't want to be told what to do by liberals" could net us Kansas, Oklahoma, Kentucky, Indiana, North Dakota, South Dakota, Wyoming, Montana, Idaho, Alaska, Utah, West Virginia, Nebraska. That's 36. Bribe Nevada and Maine and that's the state houses.
Do you really think that we couldn't get 2/3 of the vote in the Senate and House, if the blue state representatives and Senators (that's most of the Democrats) were to joing the looney GOP to vote in favor?
Maybe. However, I have a VERY hard time seeing any of those state legislatures listed NOT voting to kick out New York and California even if it's kill their economies.
And Stressed lines, few of your fellow conservatives agree, and I think once the blue states start adding up, they'll realize pretty fast they're WAY better off outside the US. half the country is just a backward drag those states just don't need.
Except for sentiment, I'm not sure what the rationale for keeping the US together is. Half the country isn't going to want to be under a perennially unrepresentative government, and the other half hates the folks they're lording it over.
Ultimately, a profoundly unrepresentative institution like the federal government is going to have some serious serious strains. Eventually, it will split up, one way or another.