Common core does have ONE good point about it. There is a problem with states having different levels of what a student should know by what ever grade they are finishing. Assume a parent moves from Missouri to Florida, they have a kid in 10th grade. The states should have some sort of similar benchmark to determine that all 10 graders know this in these subjects. I think that the states should all get together and look at the standards and then agree on one. Keep the fed out of it.
Not a good idea at all.
The problem you describe has never been a big problem.
The ultimate ideal would be no "public" in education. Anything any government touches, it ultimately destroys.
If the States standardized, then without a doubt the evil left would somehow take over the curriculum and continue the progressive indoctrination. As it is, evil governments control 90% of K-12.
The marketplace would provide a superior product, if the parasites in government would get out of the way.