The whole proficient-or-left-behind dichotomy is, of course, phony. Achievement, reasonably defined, is a continuum, not part of an either/or. If we set the standard for "proficient" as a score of 80, would a student who scores 79 be "left behind?" To say so would be absurd, but that's how NCLB operates.
Moreover, the whole debate focuses on the wrong thing. From Jefferson's time through the 1940's the schools' function was civic. Jefferson argued that all governments degenerate and to prevent this, the people themselves needed to be educated. It is only in the post-Sputnik years that the focus has shifted, mistakenly, from education as necessary to preserve democracy test scores uber alles as necessary to get a job and keep America competitive in the global economy.
But test scores tell us little in the long run. A 1974 paper from the American College Testing Program stated, "We conclude that academic talent as measured by test scores, high school grades and college grades is not related to significant adult accomplishment. Though a certain level of academic talent may be necessary to complete medical school, for example, the grades of medical students appear unrelated to later success as physicians."
Thus, high-stakes testing as represented in NCLB, Texas' TAKS, Virginia's SOLs, Florida's FCAT, etc., is demoralizing and corrupting teachers and administrators by gun-barrel emphasis on something that is, in the long haul, trivial. One can only hope that some day in the future we will look back and ask "What were we thinking?
And that outcome will only remain possible, of course, if we remain able to think.