Earlier quoted context omitted.
Take a look at the recently released questions from the 2012 california math standardized tests. Looks like math, not memorization to me. Here is grade 7: http://www.cde.ca.gov/ta/tg/sr/documents/cstrtqmath7.pdf Here is algebra: http://www.cde.ca.gov/ta/tg/sr/documents/cstrtqalgebra.pdf
Now show me the same test from Alabama, or North Carolina. Chances are it's not of the same quality. California actually has a relatively good educational system, compared to the rest of the country.
And I'm teaching someone grade 7 math in North Carolina, so this is something I care about a lot.
There's not a whole lot of secret sauce in a multiple-choice test. Yes, you can do them well or you can do them poorly. But even if you were to assume that California has super-awesome math tests, it would be pretty easy to duplicate them elsewhere.