Fundamental questions about the Common Core standards

Why do the Common Core educational standards (e.g., a list of what needs to be taught in each grade dreamed up by David Coleman) need to be common across the country? Why is it crucially important that 45 states upend what they're doing to jump on board this untested bandwagon? Wouldn't it make more sense to test Dave's brainstorm in one state to see if it actually works before betting the country on it?

For example, a couple of decades ago, the state of California had a great idea: stop teaching kids to read using phonics and use only whole word instruction instead, because studies prove that really good adult readers are whole word readers (e.g., "whooping cough" pretty much equals "whooping crane" in the eyes of the fastest readers). This proved a famous disaster. For years afterward, you could look at California test scores and instantly tell which grades the poor kids who got stuck with whole word instruction were in by how much lower the reading scores were of, say, eighth through tenth graders versus seventh or eleventh graders.

Fortunately, due to our federal system, that only happened in one state (granted, the state that is 1/8th of the country), and other states learned salutary lessons from California's mistake.

The only argument I've heard for why a Common Core being must be almost nationally common is that it would be nice for students who suddenly move from one state to another to find their new school is exactly where their old school left off. But how important is this?

The French minister of education is famously proud that in every school in the country the nine-year-olds are reading the same page at the same moment. Is this better or worse than a more federal system like Germany's? Off hand, the results don't seem all that different. The differing approaches seems more to reflect the French state's obsession with centralization in case they want to put together an army big enough invade Russia again. In contrast, German federalism reflects their interest in decentralization so they aren't tempted to put together an army big enough to invade Russia again.

Moreover, what is the point of lockstep standards, anyway? How do they survive their collision with the reality of human diversity? If you say that all students must learn U, V, and W in 4th grade so they will be prepared to learn X, Y, and Z in 5th grade, what happens to the students who fail to learn V and W in 4th grade and thus aren't ready for X,Y, and Z if fifth grade? What about the students who learned U,V, and W in the first months of 4th grade?

And shouldn't somebody, somewhere test the Common Core before it's rolled out to 45 states?

Education Realist writes:

I’ve stayed out of the Common Core nonsense. The objections involve much fuss about federal control, teacher training, curriculum mandates, and the constructivist nature of the standards. Yes, mostly. But so what? 

Here’s the only important thing you need to know about Common Core standards: they’re ridiculously, impossibly difficult.

America is just finishing up a colossal failure called No Child Left Behind, a plan dreamed up by President Bush and Senator Kennedy that mandated that every public school student in America score "proficient" in reading and math by next May. It was obvious from the get-go that it would never work, but it was wildly popular within the education industry for many years because it justified no end of conferences, meetings, pet projects, days out of the classroom to get "professional development," and all the other things that are more fun than teaching other people's children day after day after day.

Now that NCLB is dying, we have a whole new fad that is suspiciously like the old one.