I don't think the author is ever making the claim that federal spending should be proportionate to tax levied from that state. He's just using the data point th

I don't think the author is ever making the claim that federal spending should be proportionate to tax levied from that state. He's just using the data point that CA is still a net source, not sink, of federal tax dollars as evidence for his thesis that CA is not on the brink of collapse. His last sentence about succession is only meant to counter hyperbole with hyperbole.