A challenge with poverty rates in the US is that they often essentially proxy for "what proportion of the population recently immigrated from low-wage countries"; immigration from e.g. Mexico to the US often causes the poverty rate in both countries to rise and every actual human to be better off. California has ~10 million immigrants; many of them arrived rather recently.
(I think this is a variation on Simpson's paradox.)
(I think this is a variation on Simpson's paradox.)