That comes from this chart, which is interesting. The highest scoring state, Iowa, only has 3% of students taking the test, presumably the brightest 3%. Maine, at the bottom, has a pretty remarkable 92% of students taking the test. “Maine is dumb” is hardly a fair conclusion, I think.
(Also, apparently they’ve added another section, writing, to the SATs, making what used to be a good score now a crappy one. Didn’t know that.)